Adding more Variant types

[Guiguiprim]

Suggestion

Hey,

Using windows-rs 0.52.0 I had my own Variant helper.
In windows-rs 0.54.0 I see that windows::core::Variant was added, which is nice.
With that change, all Windows::Win32::System::Variant::VARIANT* where removed (which completely breaks my Variant implementation).

I would be happy to migrate to windows::core::Variant but it is missing types support that I used:

• fn null() -> Variant to construct a VT_NULL variant
• TryFrom<&[String]> for Variant to construct VT_ARRAY_BSTR variant
• TryFrom<&[u8]> for Variant to construct VT_ARRAY_UI1 variant

If I can, I'm going to have a try at it.

[kennykerr]

Happy to review additions. I assume you mean VT_ARRAY | VT_BSTR and so on.

[hcldan]

We also need VT_ARRAY and VT_BSTR support.

[kennykerr]

VT_BSTR is already supported. It's really just VT_ARRAY that I hope to get to soon.

[hcldan]

Excellent!