Add a test for signrawtransaction with various sighashes parameters

Summary:
While reviewing D2007 @jasonbcox raised that there was not test for the
various errors thrown when signrawtransaction is called with an
invalid sighash parameter.
This diff adds a functional test case which check the output of
signrawtransaction against valid sighashes, invalid sighashes and
sighashes missing the FORKID flag.

Test Plan:

./test/functional/test_runner.py rpc_signrawtransaction

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Subscribers: teamcity, schancel, jasonbcox

Differential Revision: https://reviews.bitcoinabc.org/D2560