Database: Add *sort fields, bpm, mood, initial_key

Upgrade from schema version 20 to 21. This includes:

- six fields for sort tags
- new fields bpm, mood, initial_key

See https://github.com/strawberrymusicplayer/strawberry/pull/1779#pullrequestreview-3003042802

data/schema/schema-21.sql

@@ -0,0 +1,43 @@
+DROP INDEX IF EXISTS idx_albumartistsort;
+
+DROP INDEX IF EXISTS idx_albumsort;
+
+DROP INDEX IF EXISTS idx_artistsort;
+
+DROP INDEX IF EXISTS idx_composersort;
+
+DROP INDEX IF EXISTS idx_performersort;
+
+DROP INDEX IF EXISTS idx_titlesort;
+
+ALTER TABLE %allsongstables ADD COLUMN albumartistsort TEXT;
+
+ALTER TABLE %allsongstables ADD COLUMN albumsort TEXT;
+
+ALTER TABLE %allsongstables ADD COLUMN artistsort TEXT;
+
+ALTER TABLE %allsongstables ADD COLUMN composersort TEXT;
+
+ALTER TABLE %allsongstables ADD COLUMN performersort TEXT;
+
+ALTER TABLE %allsongstables ADD COLUMN titlesort TEXT;
+
+ALTER TABLE %allsongstables ADD COLUMN bpm REAL;
+
+ALTER TABLE %allsongstables ADD COLUMN mood TEXT;
+
+ALTER TABLE %allsongstables ADD COLUMN initial_key TEXT;
+
+CREATE INDEX IF NOT EXISTS idx_albumartistsort ON songs (albumartistsort);
+
+CREATE INDEX IF NOT EXISTS idx_albumsort ON songs (album);
+
+CREATE INDEX IF NOT EXISTS idx_artistsort ON songs (artistsort);
+
+CREATE INDEX IF NOT EXISTS idx_composersort ON songs (title);
+
+CREATE INDEX IF NOT EXISTS idx_performersort ON songs (title);
+
+CREATE INDEX IF NOT EXISTS idx_titlesort ON songs (title);
+
+UPDATE schema_version SET version=21;