tests: Add fuzzing harness for CheckBlock(...) and other CBlock related functions

Summary:

Add fuzzing harness for CheckBlock(...) and other CBlock related
functions.

Backport of core PR17071.

The missing corpora change is not relevant for us.

Test Plan:

ninja bitcoin-fuzzers
./test/fuzz/test_runner.py <path_to_corpus>

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D8151