Support more parameter types in COM interface declarations

[Herschel]

Motivation

COM interface declaration support was initially added in #1540. Currently it only supports parameters of pointer type which can be passed through the FFI boundary.

For example, the following fails:

#[interface("00000000-0000-0000-0000-000000000000")]
unsafe trait ITest: IUnknown {
    fn SetFoo(&self, i: i32) -> HRESULT;
}

This should support more parameter types, including primitive types and common Windows API types which can also be passed through based on something like AbiTransferable in com-rs.

(Naturally this is all a very recent addition, still under development and not expected to be working yet -- submitting this for tracking purposes. Thank you!)

[kennykerr]

Yep, that was only the start. I hope to support the same type-system as the rest of the windows crate supports.

Starting to work on this now.

[kennykerr]

Tracking this here: #1486

[Herschel]

#1486 was re-opened, so closing this in favor of that issue. Thank you for the efforts!

[kennykerr]

Improvements to the interface macro are now published as part of 0.34.0.