[music] Attempts to fix bad lookups from LastFM and Jellyfin

Broader issue was creating tracks without albums that were duplicates of
existing tracks because sometimes Jellyfin and LastFM do not have albums
sent with them.

vrobbler/apps/scrobbles/mixins.py

@@ -124,12 +124,12 @@ class ScrobblableMixin(TimeStampedModel):
         logger.warning("fix_metadata() not implemented yet")
 
     @classmethod
-    def find_or_create(cls) -> None:
+    def find_or_create(cls):
         logger.warning("find_or_create() not implemented yet")
 
-    def __str__(self):
+    def __str__(self) -> str:
         if self.title:
-            return self.title
+            return str(self.title)
         return str(self.uuid)