Fixed bad FWLink

[rpetrusha]

Fixed bad FWLink

In addition to fixing the link described in #6056, this PR:

• replaces tokens with simple token text.
• fences Win32 APIs and constants and adds links to them.

Fixes #6056

[mairaw]

For this kind of broken link report we've been getting, I try to first find the sample under https://github.com/Microsoft/WPF-Samples. If I can't find it, I'm linking to the location of the sample in our samples repo and also updating the FwLink in case an external resource is also using the same link.

The problem of linking to that vs.90 page is that the download sample link is dead there too.

[mairaw]

It seems the sample exissts under https://github.com/Microsoft/WPF-Samples/tree/master/Migration%20and%20Interoperability/WPFHostingWin32Control not sure though if the docs match that.

[mairaw]

LGTM. Would just change the sample FwLink to go to https://github.com/Microsoft/WPF-Samples/tree/master/Migration%20and%20Interoperability/WPFHostingWin32Control instead.