Use viem Hash and Address classes to validade strings

[alvarengathomas]

Just a heads-up, viem already has support for Hash (it even has Typescript support) and some functions to work with. It also offers some functions to ensure strings are hashes. The same goes for addresses (And functions to check if a given string is an address). You may want to work with those instead of using custom implementations here (or, make a blend of both options if needed)

Originally posted by @gndelia in #3 (comment)