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

src/google_auth.proto

@@ -0,0 +1,32 @@
+syntax = "proto3";
+
+// Copied from: https://github.com/beemdevelopment/Aegis/blob/master/app/src/main/proto/google_auth.proto
+
+message MigrationPayload {
+  enum Algorithm {
+    ALGO_INVALID = 0;
+    ALGO_SHA1 = 1;
+  }
+
+  enum OtpType {
+    OTP_INVALID = 0;
+    OTP_HOTP = 1;
+    OTP_TOTP = 2;
+  }
+
+  message OtpParameters {
+    bytes secret = 1;
+    string name = 2;
+    string issuer = 3;
+    Algorithm algorithm = 4;
+    int32 digits = 5;
+    OtpType type = 6;
+    int64 counter = 7;
+  }
+
+  repeated OtpParameters otp_parameters = 1;
+  int32 version = 2;
+  int32 batch_size = 3;
+  int32 batch_index = 4;
+  int32 batch_id = 5;
+}