add hook helpers library

[xyek]

This PR adds hook helper library which automates the calculation of flags in the deployment/testing scripts.

[saucepoint]

hi thanks for the PR!

i think this syntax is interesting, but we're likely to move hook test deployments to use foundry cheatcodes (deployCodeTo)

[xyek]

That makes sense, how would the deployCodeTo address be calculated? Just this code to be updated right?

Do you think I can do that in this PR? Or is it in the works already?

[saucepoint]

the PR to move to deployCodeTo lives here #122

taking a look at this PR again, I'm quite hesitant on defining an arbitrary solidity function outside of a contract. The pattern feels a little too unnatural

if my understanding is correct, this PR lets hook developers adjust their flags in 1 place without needing to update test & scripts. Useful, but I dont think hook developers are changing their flags all that often. Thank you for the consideration!