We need to reuse almost all of the gossip infrastructure for accounting
transactions, with the only difference being that accounting will use a
`Transfer` message rather than a `VAA`.
Make the observation stored in the processor state generic so that it
can be either a VAA or a Transfer. The rest of the code is shared.
Optional metadata for debugging. Allows tying a received observation
to an on-chain transaction even if the node missed the observation.
Change-Id: Ie50c10c8ab7f65469555674d90645f91092fb2e3
Chirantan Ekbote
tbjump
justinschuldt
Leo