Get album info (when available) from Last.fm, add getAlbumInfo endpoint (#2061)

* lastfm album.getInfo, getAlbuminfo(2) endpoints

* ... for description and reduce not found log level

* address first comments

* return all images

* Update migration timestamp

* Handle a few edge cases

* Add CoverArtPriority option to retrieve albumart from external sources

* Make agents methods more descriptive

* Use Last.fm name consistently

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

core/agents/interfaces.go

@@ -13,12 +13,20 @@ type Interface interface {
 	AgentName() string
 }
 
+type AlbumInfo struct {
+	Name        string
+	MBID        string
+	Description string
+	URL         string
+	Images      []ExternalImage
+}
+
 type Artist struct {
 	Name string
 	MBID string
 }
 
-type ArtistImage struct {
+type ExternalImage struct {
 	URL  string
 	Size int
 }
@@ -32,28 +40,32 @@ var (
 	ErrNotFound = errors.New("not found")
 )
 
+type AlbumInfoRetriever interface {
+	GetAlbumInfo(ctx context.Context, name, artist, mbid string) (*AlbumInfo, error)
+}
+
 type ArtistMBIDRetriever interface {
-	GetMBID(ctx context.Context, id string, name string) (string, error)
+	GetArtistMBID(ctx context.Context, id string, name string) (string, error)
 }
 
 type ArtistURLRetriever interface {
-	GetURL(ctx context.Context, id, name, mbid string) (string, error)
+	GetArtistURL(ctx context.Context, id, name, mbid string) (string, error)
 }
 
 type ArtistBiographyRetriever interface {
-	GetBiography(ctx context.Context, id, name, mbid string) (string, error)
+	GetArtistBiography(ctx context.Context, id, name, mbid string) (string, error)
 }
 
 type ArtistSimilarRetriever interface {
-	GetSimilar(ctx context.Context, id, name, mbid string, limit int) ([]Artist, error)
+	GetSimilarArtists(ctx context.Context, id, name, mbid string, limit int) ([]Artist, error)
 }
 
 type ArtistImageRetriever interface {
-	GetImages(ctx context.Context, id, name, mbid string) ([]ArtistImage, error)
+	GetArtistImages(ctx context.Context, id, name, mbid string) ([]ExternalImage, error)
 }
 
 type ArtistTopSongsRetriever interface {
-	GetTopSongs(ctx context.Context, id, artistName, mbid string, count int) ([]Song, error)
+	GetArtistTopSongs(ctx context.Context, id, artistName, mbid string, count int) ([]Song, error)
 }
 
 var Map map[string]Constructor