Fix Win32 build errors.

[crud89]

Describe the pull request

This PR fixes some issues with the x86 build, namely:

• Properly prevents attempts to include pix3.h if not available (regression from Use open source PIX runtime instead of NuGet pre-build. #133).
• Template resolution errors with exception constructors, if uint64_t is not natively available.
• An occasion where nullptr was used instead of VK_NULL_HANDLE.
• A generator issue causing access violation on x86 release builds.

Additionally, this PR forces the CI builds to use the release profile and removes the publish profiles.