Playback Manager Rewrite and Custom Server

[KRTirtho]

In this PR,

• Custom Server is created to replace previously locally track match (Spotify→YouTube) metadata caching
  • This change will allow us to store all valuable metadata in a central server accessible to all
  • The server is completely open to read but for now only official Spotube app is allowed to mutate
  • It'll store multiple YouTube matches of Spotify Tracks and has a voting system where when a user changes a track source, the new source gets upvoted, which will result in the upvoted source to be listed upwards whenever fetched next. This will ensure accurate matching of a Spotify Track and should theoretically resolve
    • No way to fix a song playing an incorrect audio / Song listing is different to what is played (Android) #244
    • [Wrong song] <while the thumbnail remains identical the music is completely different> #196
  • Support for storing lyric match metadata is also planned
• fixed old playback manager and was re-written to support Queue based playback
• Playlist/Playback has been made immutable to prevent mutability related hidden bugs
• Playback has been broken in to smaller sections, which makes it easier to modify or debug it
• Pre-download and Play is enabled for Desktop & caching support for pre downloaded tracks