[Target v0.19] Deprecate and add test for signrawtransaction

Summary:
Deprecate signrawtransaction (target is v0.19).

Backport 3/3 of core PR10579 (part of commit d602348 + deprecation from 1e79c05)

Depends on D2763
Completes task T438

Test Plan:

make check
./test/functional/test_runner.py --extended

Reviewers: #bitcoin_abc, jasonbcox, deadalnix

Reviewed By: #bitcoin_abc, jasonbcox, deadalnix

Subscribers: deadalnix, teamcity

Differential Revision: https://reviews.bitcoinabc.org/D2009