capture QR codes from camera and major refactoring

- add GUI for QR code capturing from camera (CV2 is used)
- support different QR readers: ZBAR,QREADER,QREADER_DEEP,CV2,CV2_WECHAT
- support several input files
- add option to ignore duplicate otps
- write warnings and errors to stderr
- add output coloring
- rename project from extract_otp_secret_keys to extract_otp_secrets
- improve help
- clean verbose level output
- use Python type hints and check with mypy
- use f-strings
- clean up code
- add more tests
- calculate code coverage
- use src-layout: move files and folders
- support wheel packing
- enhance README.md
- bugfixes
    * fix -k -
    * fix utf-8 encoding on windows

.gitignore

@@ -9,10 +9,13 @@ venv/
 !example_output.csv
 !.github/
 !.flake8
-.vscode
-!.vscode/settings.json
+!.vscode/
 !.devcontainer/
 !.devcontainer/*.json
 *.whl
 build/
-extract_otp_secret_keys.egg-info/
+dist/
+*.egg-info/
+*.xml
+pytest-coverage.txt
+tests/reports/