[Feature] Album Artists browsing and article-aware sorting

[Sc00tz]

Album Artists browsing and article-aware sorting

• Add AlbumArtistStore for cleaner artist browsing separate from track artists
• Implement article-aware sorting utility that removes articles (The, A, An, etc.) for sorting
• Support multiple language articles (English, Spanish, French, German, Italian, Portuguese, Dutch)
• Add /api/albumartist/* endpoints for album artist operations
• Extend /api/getall/ to support 'albumartists' itemtype
• Update artist name sorting to use article-stripped keys while preserving display names
• Add library statistics endpoint including album artist counts

Features:

• 'The B-52's' now sorts under 'B' instead of 'T'
• Album Artists shows primary artists without featured/collaboration clutter
• Fully backward compatible with existing functionality
• No database schema changes required - builds from existing track metadata

API endpoints added:

• GET /api/albumartist/{hash} - Get album artist details
• GET /api/albumartist/{hash}/albums - Get albums by album artist
• GET /api/albumartist/{hash}/tracks - Get tracks by album artist
• GET /api/albumartist/search - Search album artists
• GET /api/albumartist/stats - Album artist statistics
• GET /api/getall/albumartists - Browse all album artists
• GET /api/getall/stats - Library statistics"

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

The PR fulfills these requirements:

• When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx[,#xxx], where "xxx" is the issue number)

If adding a new feature, the PR's description includes:

• A convincing reason for adding this feature (it's best to open a suggestion issue first and wait for approval before working on it)

Other information:

[michilyy]

Hello @Sc00tz ,
Thank you for your support.

While looking through your commits I detected some commends like # Added this line
Could you please explain, why you added these comments?
I do not seem to fully understand what information the comment provide.

Thanks you