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_test.go

@@ -136,6 +136,10 @@ var _ = Describe("sqlRepository", func() {
 	})
 
 	Describe("buildSortOrder", func() {
+		BeforeEach(func() {
+			r.sortMappings = map[string]string{}
+		})
+
 		Context("single field", func() {
 			It("sorts by specified field", func() {
 				sql := r.buildSortOrder("name", "desc")
@@ -163,6 +167,14 @@ var _ = Describe("sqlRepository", func() {
 				sql := r.buildSortOrder("name desc, age, status asc", "desc")
 				Expect(sql).To(Equal("name asc, age desc, status desc"))
 			})
+			It("handles spaces in mapped field", func() {
+				r.sortMappings = map[string]string{
+					"has_lyrics": "(lyrics != '[]'), updated_at",
+				}
+				sql := r.buildSortOrder("has_lyrics", "desc")
+				Expect(sql).To(Equal("(lyrics != '[]') desc, updated_at desc"))
+			})
+
 		})
 		Context("function fields", func() {
 			It("handles functions with multiple params", func() {