separates the resolving step from the QEInvoiceParser so the 'recipient'
can be resolved first and then either an QEInvoiceParser can be used if
it is a sending request that has been resolved (invoice, address,
lnurlp, ...), or RequestDetails can be used if the resolved 'recipient'
turns out to be a voucher/LNURLW string.
# Conflicts:
# electrum/gui/qml/qeinvoice.py