Kafka token transfer topics now include bodies for delete events

For our Kafka topics in the format of *.transfer.incremental.v2, we made an improvement to how delete events are sent.

Previously, messages indicating the delete of a transfer (which are rare, usually indicating a re-org event) were sent as empty messages, with a modType of DELETE.

Moving forward, delete messages will be sent with the same header, but with the message body included, to provide more detail