Resolve Solidity paths in sol!

[DaniPopes]

Custom types are Solidity paths, and currently we panic if it's longer than 1 ident.

[DaniPopes]

This is now implemented

sol! {
    interface I {
        struct S {
            uint x;
        }
    }
    function func(I.S memory stuff);
}

let _ = funcCall { stuff: I::S { x: U256::ZERO } };