[Cashtab] [Chronik Websocket Notifications] [Part 6] Parse eToken txs from websocket msg

Summary:
T2447

Depends on D11536

Parse eToken information from websocket received txs

Test Plan:
Review modifications to the parseChronikTx function
npm test

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Subscribers: emack

Differential Revision: https://reviews.bitcoinabc.org/D11537