feat: add human-readable ABI parser

[alessandromazza98]

Closes #291

This is a draft just to let you know how I'm trying to solve it @DaniPopes.

Right now I implemented a parse method only for Error but the code is easily re-usable.
Also now all my code is inside item.rs but I can move most of the real parser logic inside alloy-sol-type-parser as you suggest in the issue description (maybe in a new file inside of that?)

I also add some tests so that you can see how it works. Also these tests are in the item.rs file but I can move them somewhere else.

PS: of course the CI gives error because I used println! in the tests just to have a quick view of how the parsing work. Later I can delete them or change them with the use of assert

[DaniPopes]

BTW we recently started using winnow for parsing, see #292. All this should be doing is calling into sol_type_parser::{RootType,TupleSpecifier}::parse

[alessandromazza98]

BTW we recently started using winnow for parsing, see #292. All this should be doing is calling into sol_type_parser::{RootType,TupleSpecifier}::parse

Oh ok thanks for the information. I'll edit it

[gakonst]

Superseded by #329! Thank you for taking this on @alessandromazza98