Partially replaces #7310, only for the transaction verification part. Like in core_io.h we can separate the cpp files instead of using a single consensus.cpp. I would like to know what is preferred in that reward as soon as possible: I won’t fight either way because I don’t care (until something has been decided then I will become a fanatic against changing the decision because I may waste seconds renaming things while rebasing interactively with some of my outdated branches).
Based in #8328 out of laziness, it can be easily separated if necessary.