fix(subsonic): Sort songs by presence of lyrics for getLyrics (#4237)

* fix(subsonic): Sort songs by presence of lyrics for `getLyrics`

The current implementation of `getLyrics` fetches any songs matching the artist and title.
However, this misses a case where there may be multiple matches for the same artist/song, and one has lyrics while the other doesn't.
Resolve this by adding a custom SQL dynamic column that checks for the presence of lyrics.

* add options to selectMediaFile, update test

* more robust testing of GetAllByLyrics

* fix(subsonic): refactor GetAllByLyrics to GetAll with lyrics sorting

Signed-off-by: Deluan <deluan@navidrome.org>

* use has_lyrics, and properly support multiple sort parts

* better handle complicated internal sorts

* just use a simpler filter

* add note to setSortMappings

* remove custom sort mapping, improve test with different updatedat

* refactor tests and mock

Signed-off-by: Deluan <deluan@navidrome.org>

* default order when not specified is `asc`

Signed-off-by: Deluan <deluan@navidrome.org>

---------

Signed-off-by: Deluan <deluan@navidrome.org>
Co-authored-by: Deluan <deluan@navidrome.org>

persistence/sql_base_repository.go

@@ -86,6 +86,10 @@ func (r *sqlRepository) registerModel(instance any, filters map[string]filterFun
 // which gives precedence to sort tags.
 // Ex: order_title => (coalesce(nullif(sort_title,”),order_title) collate nocase)
 // To avoid performance issues, indexes should be created for these sort expressions
+//
+// NOTE: if an individual item has spaces, it should be wrapped in parentheses. For example,
+// you should write "(lyrics != '[]')". This prevents the item being split unexpectedly.
+// Without parentheses, "lyrics != '[]'" would be mapped as simply "lyrics"
 func (r *sqlRepository) setSortMappings(mappings map[string]string, tableName ...string) {
 	tn := r.tableName
 	if len(tableName) > 0 {