4a87c5cfdf7dd72d999ebeaf17db6695a7c6298d [refactor] Rewrite AcceptToMemoryPoolWorker() using smaller parts (Suhas Daftuar)
Pull request description:
This is in preparation for re-using these validation components for a new version of AcceptToMemoryPool() that can operate on multiple transactions ("package relay").
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Because of how our code handles SigChecks I could not remove the "Validate input scripts against
standard script flags" from the new PreChecks function into the PR's new PolicyScriptChecks, since
after D5128 anything related to that number can only be run after CheckInputs.
The other code in the above new function was related to SegWit therefore I just removed the
PolicyScriptChecks function.
Other missing members of the Workspace and ATMPArgs that were unused due to us not having RBF
were also taken out.
Backport of Core PR16400