[Cashtab] Parse PayButton txs in tx history

Summary:
T3423

Parse PayButton txs in tx history

Note: this will still render such txs as 'external msgs', but they will at least be legible. Will handle the msg titling issue in a separate diff, as parseChronikTx should be refactored to give an app name instead of a series of app flags.

Test Plan: npm test

Reviewers: #bitcoin_abc, Klakurka, Fabien

Reviewed By: #bitcoin_abc, Klakurka, Fabien

Subscribers: Fabien, Klakurka

Differential Revision: https://reviews.bitcoinabc.org/D15319