Threading version to try to serve connections in parallel

[msaelices]

It's a WIP, not working because of this error when the second client connects:

❯ mojo -D LOG_LEVEL=DEBUG -I ../../src/ server.mojo                                                                                                                                                                                                           
                                                                                                                                                                                                                                                              
🔥 Listening on ws://127.0.0.1:8001                                                                                                                                                                                                                           
Ready to accept connections...                                                                                                                                                                                                                                
DEBUG - Connection accepted! IP: 127.0.0.1 Port: 56254                                                                                                                                                                                                        
DEBUG - Connection accepted! IP: S1 Port: 56254                                                                                                                                                                                                               
DEBUG - Bytes received: 153                                                                                                                                                                                                                                   
DEBUG - Starting handshake                                                                                                                                                                                                                                    
DEBUG - Sending handshake response                                                                                                                                                                                                                            
DEBUG - Setting state to:  1                                                                                                                                                                                                                                  
DEBUG - Bytes written: 169                                                                                                                                                                                                                                    
DEBUG - S1 56254                                                                                                                                                                                                                                              
DEBUG - Bytes received: 11                                                                                                                                                                                                                                    
<<<  hello                                                                                                                                                                                                                                                    
>>>  hello                                                                                                                                                                                                                                                    
DEBUG - S1 56254                                                                                                                                                                                                                                              
DEBUG - Connection accepted! IP: 127.0.0.1 Port: 47966                                                                                                                                                                                                        
DEBUG - Connection accepted! IP: pS1 Port: 47966                                                                                                                                                                                                              
DEBUG - Bytes received: 153                                                                                                                                                                                                                                   
DEBUG - Starting handshake                                                                                                                                                                                                                                    
[3188977:3188977:20250221,003637.194120:ERROR elf_dynamic_array_reader.h:64] tag not found                                                                                                                                                                    
[3188977:3188977:20250221,003637.194210:ERROR elf_dynamic_array_reader.h:64] tag not found                                                                                                                                                                    
Please submit a bug report to https://github.com/modular/mojo/issues and include the crash backtrace along with all the relevant source codes.                                                                                                                
[3188977:3188978:20250221,003637.197080:ERROR directory_reader_posix.cc:42] opendir /home/msaelices/src/my-repos/mojo-websockets/.magic/envs/default/share/max/crashdb/attachments/974366e3-ddd2-4c4e-a9ef-99d8efa4edc9: No such file or directory (2)        
#0 0x000056f9d8820bfb llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) Signals.cpp:0:0                                                                                                                                                                     
#1 0x000056f9d881ea69 llvm::sys::RunSignalHandlers() Signals.cpp:0:0                                                                                                                                                                                          
#2 0x000056f9d882126d SignalHandler(int) Signals.cpp:0:0                                                                                                                                                                                                      
#3 0x000074c482445330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)                                                                                                                                                                                               
#4 0x000074c45e9f9aae _PyInterpreterState_GET /usr/local/src/conda/python-3.12.8/Include/internal/pycore_pystate.h:133:18                                                                                                                                     
#5 0x000074c45e9f9aae get_state /usr/local/src/conda/python-3.12.8/Objects/obmalloc.c:866:34
#6 0x000074c45e9f9aae _PyObject_Malloc /usr/local/src/conda/python-3.12.8/Objects/obmalloc.c:1563:22
#7 0x000074c45e9f9aae PyObject_Malloc /usr/local/src/conda/python-3.12.8/Objects/obmalloc.c:801:12
#8 0x000074c45e9f9aae PyUnicode_New /usr/local/src/conda/python-3.12.8/Objects/unicodeobject.c:1368:24
#9 0x000074c45e9f9aae unicode_decode_utf8 /usr/local/src/conda/python-3.12.8/Objects/unicodeobject.c:4872:19
#10 0x000074c45eae4608 PyImport_ImportModule /usr/local/src/conda/python-3.12.8/Python/import.c:2487:0
#11 0x000074c3e80271ea                                         
mojo crashed!                                                  
Please file a bug report.                                      
Segmentation fault (core dumped)