Crash debug builds when mempool ConsensusScriptChecks fails

Summary:

Currently a bug in the function might sneak around our testing infrastructure.

Fix that by turning bugs into crashes during tests.

This is a backport of core#23590

Test Plan:
With and without DEBUG:
ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D12416