T1757
utxos is set in state in useWallet.js so that the app can compare the most recently fetched utxo set with the previously fetched utxo set and determine whether or not it has changed, i.e. a transaction was sent or received.
Cashtab has since migrated to keeping wallet state in localstorage, including utxos. Right now the field is duplicated, existing both in wallet.state and in react state for useWallet.js.
This diff replaces the legacy utxos state field with the current wallet.state, so that there is one source of truth.