script destinations.
This is mainly to support OP_RETURN outputs, which typically have a zero amount output value,
but as we don't special case OP_RETURN, this is currently done for all non-address scripts
Also, it's probably good to add a warning popup for OP_RETURN outputs with a non-zero output value, but this
would also need special casing for OP_RETURN.
Saving of script output payment identifiers is disabled for now, as reading the script from the stored invoice
back into human-readable form is currently not implemented, and currently only lightning invoices or address output
is supported.
```
$ ./run_electrum sadasdasddsa
Traceback (most recent call last):
File "/home/user/wspace/electrum/./run_electrum", line 532, in <module>
main()
File "/home/user/wspace/electrum/./run_electrum", line 398, in main
if uri and not PaymentIdentifier(None, uri).is_valid():
File "/home/user/wspace/electrum/electrum/payment_identifier.py", line 136, in __init__
self.parse(text)
File "/home/user/wspace/electrum/electrum/payment_identifier.py", line 265, in parse
elif contact := self.contacts.by_name(text):
AttributeError: 'NoneType' object has no attribute 'by_name'
```
regression from https://github.com/spesmilo/electrum/pull/8462
- pr.verify() was called in qml, but not in qt gui
- we now call pr.verify() in get_payment_request(), to make the API less error-prone
- it is now ok to call pr.verify() multiple times, the result is cached