Rollup merge of #156956 - Jamesbarford:feat/extend-lift-generic-capabilities, r=lcnr

Support generic params in `Lift_Generic`

Handle generic type parameters, including nested occurrences, when deriving `Lift_Generic`.

This lets types like `Binder<I, T>` use `#[derive(Lift_Generic)]` instead of requiring a manual `Lift` impl.

Concretely it can now handle structs as follows;

```rs
// Generic type parameter
struct Binder<I: Interner, T> {
    // body
}

// Nested generic type parameter
pub struct Binder<I: Interner, T = SomeKind<I>> {
    //
}
```

Split off from the `Alias` refactor work; rust-lang/rust#156538

r? @lcnr

Author: JonathanBrouwer