Issue 241: Reorg code

[Tristan1900]

Change log description
Reorg the code.

• Move internal file raw_client, segment_metadata, segment_selector, reactor, segment_writer to a new module segment and remove segment prefix in their names.
• Move event_stream_writer, event_reader , reader_group related files and transaction module into a new module 'event'.
• Move bytestream to a new module byte.
• Move synchronizer, tablemap to a new module sync.
• Move trace, metric to a new module util.
• Delete error file and move individual error into related files.
• Rename event_stream_writer to event_writer.
• Rename transactional_event_stream_writer to transaction_event_writer.
• Rename byte_stream_writer and byte_stream_reader to byte_writer and byte_reader.
• Rename table_synchronizer to synchronizer.

Purpose of the change
Fix #241 #246 #240

What the code does

How to verify it
Tests should pass

[codecov-commenter]

Codecov Report

Merging #248 (b621efa) into master (94a4351) will decrease coverage by 0.81%.
The diff coverage is 81.20%.

@@            Coverage Diff             @@
##           master     #248      +/-   ##
==========================================
- Coverage   78.38%   77.57%   -0.82%     
==========================================
  Files          51       44       -7     
  Lines       10541    10323     -218     
==========================================
- Hits         8263     8008     -255     
- Misses       2278     2315      +37     

Impacted Files	Coverage Δ
config/src/lib.rs	58.33% <ø> (-39.02%)	⬇️
controller-client/src/mock_controller.rs	44.98% <ø> (ø)
src/event/writer.rs	100.00% <ø> (ø)
src/lib.rs	100.00% <ø> (+3.33%)	⬆️
wire_protocol/src/lib.rs	100.00% <ø> (ø)
src/segment/raw_client.rs	78.35% <21.42%> (ø)
shared/src/lib.rs	87.24% <25.00%> (-0.87%)	⬇️
src/segment/event.rs	50.00% <50.00%> (ø)
src/segment/writer.rs	83.84% <57.89%> (ø)
src/event/reader.rs	74.30% <75.42%> (ø)
... and 32 more