bdk_electrum: use transaction-get verbose param

[notmandatory]

"In populate_with_txids you state "because of restrictions of the Electrum API, we have to use the script_get_history call to get confirmation status of our transaction". But Electrum supports a verbose parameter to the transaction.get call, which appears to return the number of confirmations of the transaction. See https://electrumx-spesmilo.readthedocs.io/en/latest/protocol-methods.html#blockchain-transaction-get"

[LagginTimes]

I ran into a roadblock when looking into and trying to implement this:
Blockstream/electrs#36
Blockstream electrs does not yet support the verbose feature.