isDustEvent
Checks if a raw ledger event is a dust event.
Detection Strategy: Currently uses simple heuristics. In production, should:
Deserialize SCALE-encoded event
Check event discriminant/tag
Match against dust event types
Placeholder Implementation: Returns true for all events (filters in DustLocalState.replayEvents). DustLocalState will ignore non-dust events during replay.
Return
true if this is a dust event
Parameters
rawEvent
Raw ledger event from indexer