Test that a non-witness script as witness utxo is not signed

Summary:
The rpc test was aletered to add a new node or the "signer" tests run out of node to run on.

This is a partial backport of Core PR13917 : https://github.com/bitcoin/bitcoin/pull/13917/commits/7c8bffdc24e005c3044a9a80bbc227b2a39b8605

Depends on D4459 and D4470

Test Plan:

make check
./test/functional/test_runner.py

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D4475