Distinguish transfers from deposits and withdrawals

[wilsonianb]

Specify a code for Tigerbeetle transfers denoting the type.
Query account transfers by type to be able to determine things like what amount of an outgoing payments total debits are transfers as opposed to withdrawals.

[jorangreef]

@wilsonianb as soon as TB's LSM storage is running, we'll be able to provide the querying interface to query by code.

[sabineschaller]

TigerBeetle is now designing a Query API. Let's wait for that.
https://tigerbeetle.slack.com/archives/C0431SPEB61/p1679586883312349

[wilsonianb]

https://twitter.com/TigerBeetleDB/status/1638931604801302528