Integrate Spotify Playlist Management

[CodeZen404]

Is your feature request related to a problem? Please describe. Currently, after logging in with a Spotify account, users cannot see their existing Spotify playlists or manage them within SimpMusic. This limits the integration with Spotify and reduces user convenience.

Describe the solution you'd like

• View Existing Spotify Playlists: Show Spotify playlists in the library section after login.
• Create New Playlists: Allow users to create new playlists in their Spotify account.
• Add/Remove Songs: Enable users to add or remove songs from their Spotify playlists within SimpMusic.