Fix/tidal edge cases

[CptBananaCanon]

Fix additional edge cases in Spotify → Tidal sync

• Handle None values in Spotify metadata (prevents crashes in simple() and artist formatting)
• Prevent crash when Tidal rejects tracks (HTTP 412)
• Fallback to adding tracks individually if batch add fails
• Skip problematic tracks instead of aborting sync

Result:

• Sync no longer crashes on malformed Spotify data
• Sync no longer stops when Tidal rejects specific tracks
• More robust full-library migration

Tested on large real-world library with mixed content (music, spoken word, restricted tracks)

[aanzolaavila]

You saved me a lot of time to make it work, thanks a lot mate!