SourceEventFromProto converts a proto.Event to an Event NOTE: this function is used for sources implemented in external plugins so handles source events ONLY.

ArtifactExtracted is an event that is fired by an ExtractorSource when it has extracted an artifact (but not yet processed it into rows).

Base is the base struct for all events - it implements the marker function isEvent.

SourceComplete is an event that is fired when a plugin used a source has completed a source collection.

ProtoEvent is an interface for events that can be converted to a proto.Event.