[ecash-herald] Parse NFTs and agora oneshot txs

Summary:
Parse SLP1 NFT activity and agora ONESHOT activity, following the model started by agora partial parsing.

Also patches a bug in a flag variable. Tbh, getting these test mocks correct is quite time consuming, and I do not think the benefit of splitting that change out from this diff is worth the impact. Discovered in this implementation so should live here.

Going forward, will try to make these changes smaller. think this would be too crazy since "same thing as partials" ... but didn't quite work out that way.

Test Plan:
npm test, review screenshots

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Subscribers: emack

Differential Revision: https://reviews.bitcoinabc.org/D17047