Feat: add Benstalk Governance attack

[nine-december]

On Apr 16, 2022 an attacker stole $76MM from Skyward Finance.

Attack Overview
Total Lost: $76MM

Key Info Sources
Writeup: https://rekt.news/beanstalk-rekt/
Twitter: https://twitter.com/kelvinfichter/status/1515735717305008138
Twitter: https://twitter.com/peckshield/status/1515692144190648322

Principle: Business Logic - Governance Malicious Proposal with Flashloan

[nine-december]

Status Update: Added the exploit but the execution is stopping upon approvals and does not continue. I suspect that there's something with the Foundry VM.

[joaquinlpereyra]

proposal: remove this contract until we dig up what is wrong / how to reproduce.