fix(server): fix case-insensitive sort order and add indexes to improve performance (#3425)

* refactor(server): better sort mappings

* refactor(server): simplify GetIndex

* fix: recreate tables and indexes using proper collation

Also add tests to ensure proper collation

* chore: remove unused method

* fix: sort expressions

* fix: lint errors

* fix: cleanup

persistence/playlist_repository.go

@@ -55,9 +55,9 @@ func NewPlaylistRepository(ctx context.Context, db dbx.Builder) model.PlaylistRe
 		"q":     playlistFilter,
 		"smart": smartPlaylistFilter,
 	})
-	r.sortMappings = map[string]string{
+	r.setSortMappings(map[string]string{
 		"owner_name": "owner_name",
-	}
+	})
 	return r
 }