test: improve gettransaction test coverage
test: improve gettransaction test coverage

- Test gettransaction response without verbose, with verbose=False, and with verbose=True.

- In each case, test presence of expected fields in the output, including absence of the "decoded" field when `verbose` is not passed or false.

- Test that the "details" field contains the expected receive vout in each case.

DigitalPandacoin/pandacoin,peercoin/peercoin,DigitalPandacoin/pandacoin,DigitalPandacoin/pandacoin,peercoin/peercoin,peercoin/peercoin,peercoin/peercoin,peercoin/peercoin,peercoin/peercoin,DigitalPandacoin/pandacoin,DigitalPandacoin/pandacoin,DigitalPandacoin/pandacoin