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

.vscode/settings.json

@@ -2,7 +2,7 @@
     "python.testing.pytestArgs": [
         "."
     ],
-    "python.testing.unittestEnabled": false,
+    "python.testing.unittestEnabled": true,
     "python.testing.pytestEnabled": true,
     "cSpell.words": [
         "devbox",
@@ -16,5 +16,9 @@
         "qrcode",
         "TOTP",
         "venv"
-    ]
+    ],
+    "search.exclude": {
+        "**/build": true,
+        "**/dist": true
+      },
 }