feat: store and expose individual track artists

a

tags/tagcommon/tagcommmon.go

@@ -15,6 +15,7 @@ type Info interface {
 	Title() string
 	BrainzID() string
 	Artist() string
+	Artists() []string
 	Album() string
 	AlbumArtist() string
 	AlbumArtists() []string
@@ -42,6 +43,13 @@ func MustArtist(p Info) string {
 	return "Unknown Artist"
 }
 
+func MustArtists(p Info) []string {
+	if r := p.Artists(); len(r) > 0 {
+		return r
+	}
+	return []string{MustArtist(p)}
+}
+
 func MustAlbumArtist(p Info) string {
 	if r := p.AlbumArtist(); r != "" {
 		return r

tags/taglib/taglib.go

@@ -34,6 +34,7 @@ type info struct {
 func (i *info) Title() string          { return first(find(i.raw, "title")) }
 func (i *info) BrainzID() string       { return first(find(i.raw, "musicbrainz_trackid")) } // musicbrainz recording ID
 func (i *info) Artist() string         { return first(find(i.raw, "artist")) }
+func (i *info) Artists() []string      { return find(i.raw, "artists") }
 func (i *info) Album() string          { return first(find(i.raw, "album")) }
 func (i *info) AlbumArtist() string    { return first(find(i.raw, "albumartist", "album artist")) }
 func (i *info) AlbumArtists() []string { return find(i.raw, "albumartists", "album_artists") }