Add Managed->Native tests for our WinRT primitives (#23529)

Add Managed->Native tests for our WinRT primitives (#23529)

* First pass generating the contracts for the WinRT tests. Managed ones are manually written, Native are generated via C++/WinRT.

* Don't overwrite the public implementation files when we run cppwinrt

* Don't output a MIDL-processed header.

* Add default constructor for BindingViewModel.

* Partial implementation of most of the native winrt component.

* Finish implementation of native winrt component.

* Get native component building correctly (cppwinrt doesn't include wrappers for the "Windows::UI::Xaml::Interop::IBindable*" collection types.

* Add WinRT primitive marshalling tests.

* Add testing for projected types used for binding.

* Add license headers to native files.

* Disable WinRT tests on non-WinRT platforms (detection copied from CoreFX).

* Use WINDOWS_SDK_VERSION variable in all locations.

* Use Windows SDK version determined by CMake in WinRT build.

* Resolve WinMDs via globs so the build can roll between different Windows SDK versions that have required APIs seamlessly.

* Add logging of cppwinrt version.

* Try to construct path to cppwinrt when finding it

* Just directly construct the cppwinrt path.

* Remove -prefix flag from cppwinrt invocation

* PR feedback.

* Fix syntax in BindableVectorWrapper.

* Disable winrt binding test on Nano Server.

* Add enum testing. Clean up WinRT tests to hopefully build on CI (or at least fail at a later point).

* Add some more logging to try to determine why an older SDK version is being picked.

* Try to define CMAKE_SYSTEM_VERSION and see if that selects the correct SDK version (it seems to work on the build.cmd script)

* Clean up WinRT CMake now that it builds on AzDO CI.

* Disable WinRT binding test on pre-Win10V1809 systems.