[refactor] modularize code by moving logic to polyscribe crate; cleanup imports and remove redundant functions

TODO.md

@@ -11,11 +11,12 @@
 - [x] fix cli output for model display
 - [x] refactor into proper cli app
 - [x] add support for video files -> use ffmpeg to extract audio
-- detect gpus and use them
-- refactor project
+- [x] detect gpus and use them
+- [x] refactor project
 - add error handling
 - add verbose flag (--verbose | -v) + add logging
 - add documentation
+- refactor project
 - package into executable
 - add CI
 - add package build for arch linux