Depends on D11887
As per T2599, this is part of a stacked diff to sign utxos for non-eToken txs by matching wif to address.
This diff changes the signAndBuildTx() function to use getUtxosWif to obtain the funding wif rather than relying on the soon to be deprecated .wif attribute of an XEC utxo object
Includes updates to corresponding unit tests and mocks.