tests: Add fuzzing harness for {Read,Write}{LE,BE}{16,32,64} (crypto/common.h)
Summary: Backport of core PR19247.
Test Plan:
ninja bitcoin-fuzzers ./src/test/fuzz/crypto_common <path_to_corpus>
Reviewers: #bitcoin_abc, PiRK
Reviewed By: #bitcoin_abc, PiRK
Differential Revision: https://reviews.bitcoinabc.org/D9117