VS: Fix WinRT component references

WinRT components need to be referenced in a similar way that managed
code libraries are referenced.  Validate that the library reference is a
WinRT component and reference it through the project.

Add test coverage for `VS_WINRT_COMPONENT`.  While at it, fix the IOT
reference failing on Win10 SDK 17763 which doesn't include it anymore.

Fixes: #18846
Status Job ID Name Coverage
  External
passed ghostflow-check-master

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager

passed ghostflow-stager