[Cashtab] [chronik utxo handling p7] Drop bch-api utxo storage and replace with chronik

Summary:
T2447

Depends on D11964

Now that we have all the info we need for wallet utxo state from chronik instead of bch-api, set wallet state based on chronik info and not bch-api

Note: this breaks transaction sending as these functions need to be updated to account for the new storage format. This will be corrected later in the stack.

Test Plan:
npm start
Balance and token balance should match for the same wallet at Cashtab.com. Potential minor differences as Cashtab ignores all utxos of 546 sats in case they are tokens, whereas chronik approach does not.

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Differential Revision: https://reviews.bitcoinabc.org/D11966