fix: require generic trait impls to be in scope to call them

[asterite]

Description

Based on top of #6901

Problem

Part of #6864

Summary

Similar to the previous PRs, but for traits which are implemented over all types with an optional where clause, for example:

fn main() {
    let x: i32 = 1;
    let _ = x.foo(); // This will warn because there's no `use private_mod::Foo;`
}

mod private_mod {
    pub trait Foo<T> {
        fn foo(self) -> i32;
    }

    impl<T> Foo<T> for T {
        fn foo(self) -> i32 {
            42
        }
    }
}

Additional Context

Documentation

Check one:

• No documentation needed.
• Documentation included in this PR.
• [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[github-actions]

Peak Memory Sample

Program	Peak Memory
keccak256	78.51M
workspace	123.83M
regression_4709	422.94M
ram_blowup_regression	1.58G
private-kernel-tail	168.30M
private-kernel-reset	168.33M
private-kernel-inner	168.30M
parity-root	151.61M

[github-actions]

Compilation Sample

Program	Compilation Time	%
sha256_regression	1.365s	3%
regression_4709	0.797s	2%
ram_blowup_regression	15.187s	-1%
noir-contracts	15.221s	-1%