Scan existing movies

[tugcanolgun]

This issue is tied to (#10), shouldn't be complete before that issue.

A feature should be added to scan all existing movies, including the user's movies and given a list to add found movies to vigilio.

Backend

Scan

1. Scan the media folder.
2. Filter the folders that does not contain a valid video.
3. Filter the folders that already exists on vigilio
4. Return the list of folders/files.

Add

1. Should receive each movie separately with the full path to the file and an imdb id.
2. Should acquire movie info, convert the movie file, download subtitles (feature already exists)

Frontend

• A scan movies button that would make a request to the backend.
• Should list all the folder that is found.
• Upon selecting a movie, a search bar should be presented to enter imdb id (preferably, the user should be able to enter the movie's title and choose the correct movie and imdb id should be acquired)
• Add button should be added.
• Optional: Add multiple movies at once option could be beneficial.