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

extract_otp_secret_keys.code-workspace

@@ -11,10 +11,10 @@
 		"version": "0.2.0",
 		"configurations": [
             {
-                "name": "Python: extract_otp_secret_keys.py",
+                "name": "Python: extract_otp_secrets.py",
                 "type": "python",
                 "request": "launch",
-                "program": "extract_otp_secret_keys.py",
+                "program": "extract_otp_secrets.py",
                 "args": [
                     "example_export.txt"
                 ],