[sports] Big sports structure revamp

This should make scrobbling sports more like tasks.

The root scrobbled items are a little more generic, but
it's easier to see viewing patterns.

vrobbler/apps/scrobbles/models.py

@@ -884,8 +884,7 @@ class Scrobble(TimeStampedModel):
 
         # Strip log-only keys (stored in JSONField but not part of LogData dataclass)
         logdata_kwargs = {
-            k: v for k, v in log_dict.items()
-            if k in logdata_cls.__dataclass_fields__
+            k: v for k, v in log_dict.items() if k in logdata_cls().__dataclass_fields__
         }
 
         try: