feat(subsonic): add support for track/album/artist ratings/stars

fixes #171
fixes #31

* Initial code. Compiles and passes unit tests.

* Moved average rating calculation from rating fetch to set rating function. Still only compiled and unit tested.

* Bug fixes

* Fixed bug in savePlayQueue. Removed unique_index for star / rating entries because it's not valid.

* Changed time format on stars to RFC3339Nano to match created date format.

* Lint fixes.

* More lint fixes.

* Removed add* functions and replaced with Preload.

* Fixed several bugs in handlers for getStarred and getStarred2.

* Fixed bug when using music folder ID.

Co-authored-by: Brian Doherty <brian@hplaptop.dohertyfamily.me>

server/ctrlsubsonic/handlers_playlist.go

@@ -8,9 +8,9 @@ import (
 
 	"github.com/jinzhu/gorm"
 
+	"go.senan.xyz/gonic/db"
 	"go.senan.xyz/gonic/server/ctrlsubsonic/params"
 	"go.senan.xyz/gonic/server/ctrlsubsonic/spec"
-	"go.senan.xyz/gonic/db"
 )
 
 func playlistRender(c *Controller, playlist *db.Playlist) *spec.Playlist {
@@ -35,6 +35,8 @@ func playlistRender(c *Controller, playlist *db.Playlist) *spec.Playlist {
 			Where("id=?", id).
 			Preload("Album").
 			Preload("Album.TagArtist").
+			Preload("TrackStar", "user_id=?", user.ID).
+			Preload("TrackRating", "user_id=?", user.ID).
 			Find(&track).
 			Error
 		if errors.Is(err, gorm.ErrRecordNotFound) {