storage/mariadb: also optimize FavoritesOf with the same query

also fixed the query not returning songs that have never played, the
eplay JOIN should've been a LEFT JOIN.

storage/mariadb/track.go

@@ -485,45 +485,51 @@ func (ss SongStorage) UpdateHashLink(old, new radio.SongHash) error {
 }
 
 var songFavoritesOfQuery = expand(`
+WITH
+	esong
+AS (SELECT DISTINCT
+		esong.*
+	FROM
+		enick
+	JOIN
+		efave ON efave.inick = enick.id
+	JOIN
+		esong ON esong.id = efave.isong
+	WHERE
+		enick.nick = ?)
 SELECT
 	{songColumns},
 	{maybeTrackColumns},
-	{lastplayedSelect},
+	COALESCE(eplay.dt, TIMESTAMP('0000-00-00 00:00:00')) AS lastplayed,
 	NOW() AS synctime
 FROM
 	esong
 LEFT JOIN
 	tracks ON tracks.hash = esong.hash
-JOIN
-	(SELECT DISTINCT
-		esong.hash_link,
-		efave.id
+LEFT JOIN
+	(SELECT
+		MAX(dt) AS dt,
+		isong
 	FROM
-		enick
-	JOIN
-		efave ON efave.inick = enick.id
-	JOIN
-		esong ON esong.id = efave.isong
-	WHERE
-		enick.nick = ?) AS truth
-	ON esong.hash = truth.hash_link
-ORDER BY truth.id ASC
+		eplay
+	GROUP BY
+		isong) AS eplay ON eplay.isong = esong.id
 LIMIT ? OFFSET ?;
 `)
 
 var songFavoritesOfDatabaseOnlyQuery = expand(`
 WITH
 	esong
 AS (SELECT DISTINCT
-	esong.*
-FROM
-	enick
-JOIN
-	efave ON efave.inick = enick.id
-JOIN
-	esong ON esong.id = efave.isong
-WHERE
-	enick.nick = ?)
+		esong.*
+	FROM
+		enick
+	JOIN
+		efave ON efave.inick = enick.id
+	JOIN
+		esong ON esong.id = efave.isong
+	WHERE
+		enick.nick = ?)
 SELECT
 	{songColumns},
 	{trackColumns},
@@ -533,7 +539,7 @@ FROM
 	tracks
 JOIN
 	esong ON tracks.hash = esong.hash
-JOIN
+LEFT JOIN
 	(SELECT
 		MAX(dt) AS dt,
 		isong