d7290d662f fuzz: wallet, add target for Crypter (Ayush Singh)
Pull request description:
This PR adds fuzz coverage for `wallet/crypter`.
Motivation: Issue [27272](https://github.com/bitcoin/bitcoin/issues/27272#issue-1628327906)
I ran this for a long time with Sanitizers on and had no crashes; the average `exec/sec` also looks good to me. However, I would really appreciate it if some of the reviewers could try it on their machines too, and give their feedback.
ACKs for top commit:
maflcko:
utACK d7290d662f
achow101:
ACK d7290d662f
brunoerg:
utACK d7290d662f
Tree-SHA512: f5c496cabdd3263a7e1ad49eeff702725336f76bf19a82e5dbbead082e990889dd43c851d0d2d6ab740f44b8ec2aa06defd9ff6b02be68b5f8b4eaf963f88599