improve: spotify source parsing and track resolution

[ToddyTheNoobDud]

Changes

Implemented Levenshtein distance algorithm for accurate track matching, fixed explicit content handling, added automatic token refresh, and refactored code structure for better maintainability and performance.

Track selection now considers duration difference (50%), title similarity (30%), and author similarity (20%) instead of duration alone, which makes it more accurate

Why

This commit fixes "No suitable alternative stream found" for some tracks, prevents token expirations (5 minutes per token, after it gets expired another one is created/refreshed), and improves the match accuracy for searching.

Checkmarks

• [ X ] The modified endpoints have been tested.
• [ X ] Used the same indentation as the rest of the project.
• [ X ] Still compatible with LavaLink clients.

Additional information