[WIP] Create POC for fuzzing payjoin

[benalleng]

This commit adds fuzzing infrastructure for payjoin

Pull Request Checklist

Please confirm the following before requesting review:

• I have disclosed my use of
  AI
  in the body of this PR.
• I have read CONTRIBUTING.md and rebased my branch to produce hygienic commits.

[coveralls]

Pull Request Test Coverage Report for Build 19548575709

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 83.578%

---

Totals
Change from base Build 18946545260:	0.0%
Covered Lines:	8988
Relevant Lines:	10754

---

💛 - Coveralls

[benalleng]

Following the summit I thought it would be a good idea to try and follow the way that rust-lightning builds their fuzz infra https://github.com/lightningdevkit/rust-lightning/tree/main/fuzz with multiple fuzz suites, however I cannot get honggfuzz running on my machine for the life of me, maybe a personal nix problem but I also found this comment rust-fuzz/honggfuzz-rs#106 so I am not totally sure if there is a larger issue with hongfuzz at the moment.