Rewrite logging system

[pktiuk]

Closes #177
Closes #78

[pktiuk]

It appears, previous Logger implementation didn't write to files, because this functionality was not implemented.
Now we have feature parity with previous version

[pktiuk]

My bad, logging into files was implemented properly, but it is impossible to log to file and to stdout at the same time.
At the very beginning of app logs are not saved to file, because selecting file as an output occurs later.

[pktiuk]

Logs before:

$ antimicrox --log-level debug 
Debug: Socket's state:  QLocalSocket::UnconnectedState 
 ((null):0, (null))
Debug: Server name:  "" 
 ((null):0, (null))
Debug: Socket descriptor:  -1 
 ((null):0, (null))
Debug: The connection hasn't been established: 
error text ->  QLocalSocket::ServerNotFoundError 
error text 2 -> "QLocalSocket::connectToServer: Invalid name" 
 ((null):0, (null))
Debug: Socket is not valid 
 ((null):0, (null))

Logs now:

 ./build/bin/antimicrox --log-level debug 
[22:29:36.542] 🐞DEBUG  Socket's state:  QLocalSocket::UnconnectedState (file main.cpp:220)
[22:29:36.542] 🐞DEBUG  Server name:  "" (file main.cpp:221)
[22:29:36.542] 🐞DEBUG  Socket descriptor:  -1 (file main.cpp:222)
[22:29:36.542] 🐞DEBUG  The connection hasn't been established: 
                        error text ->  QLocalSocket::ServerNotFoundError 
                        error text 2 -> "QLocalSocket::connectToServer: Invalid name" (file main.cpp:223)
[22:29:36.543] 🐞DEBUG  Socket is not valid (file main.cpp:236)
[22:29:36.543] 🐞DEBUG  Socket's state:  QLocalSocket::UnconnectedState (file main.cpp:237)
[22:29:36.543] 🐞DEBUG  Server name:  "" (file main.cpp:238)
[22:29:36.543] 🐞DEBUG  Theme name:  "Pop" (file main.cpp:455)
[22:29:36.544] 🐞DEBUG  Displays don't have local data: create new instance of X11Extras (file x11extras.cpp:79)
[22:29:36.544] 🐞DEBUG  TOTAL:  102 (file qtx11keymapper.cpp:194)
[22:29:36.544] 🐞DEBUG  Display have local data (file x11extras.cpp:84)
[22:29:36.545] 🟢INFO   "Using XTest as the event generator." (file main.cpp:685)

[pktiuk]

@gombosg

Do you have any comments about this change?
In terms of interfaces, code readability, ease of use etc.