Support syncing only parts of the Supabase table (similar to Firestore subcollections)

[marceljuenemann]

Both the one-off and realtime pull handlers could add WHERE clauses to only fetch a subset of the table. The important restriction on the WHERE clause here would be that rows must never leave that "partition" of the table, otherwise the pull handler wouldn't get notified about that "deletion".

This would basically enable subcollections like in Firestore. To implement this safely, the ID of the subcollection wouldn't actually be part of the RxDB, but rather the user would create one RxDB per subcollection they want to track and then pass that ID to SupabaseReplication.