[mining] Ensure sigops and fees follow transactions during sorting
Ensure that sigOpCount and fees are attached to the proper transaction
when sorting for CTOR.
make check && ./test/functional/test_runner.py --extended
Reviewers: #bitcoin_abc, jasonbcox, akb, deadalnix
Reviewed By: #bitcoin_abc, jasonbcox, akb, deadalnix
Subscribers: akb, teamcity, jasonbcox
Differential Revision: https://reviews.bitcoinabc.org/D2047