[Cashtab] [Chronik Websocket Notifications] [Part 10] If ws connection active, hide api notifications

Summary:
T2447

Depends on D11540

This is the last part of a 10 part stacked diff to enable the feature of incoming tx notifications from websockets in Cashtab.

While this first feature 'win' is trivial, this websocket trigger will be expanded to manage wallet utxo operation going forward (instead of checking an API call at regular intervals), significantly improving the performance of the app.

Test Plan:
npm test for new function and unit tests

npm start
Receive an eToken tx and notice only one notification is fired
Receive an XEC tx and notice only one notification is fired

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Subscribers: emack

Differential Revision: https://reviews.bitcoinabc.org/D11541