[Cashtab] Update token supply when a user burns or mints

Summary: When a user burns or mints from the token page, we know the supply will be impacted. Trigger a refresh of this value on this user action.

Test Plan:
npm test, test minting and burning on cashtab.io (this is deployed there) and note the field updates after the action

unfortunately we can't directly test this without regtest, as we do not have network state changes mid integration test

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D18594