Adding CI pipeline running compiles on MSVC was one of the big shakeouts of undefined behaviour and bugs in our C++ codebase - while making that compiler happy

Adding CI pipeline running compiles on MSVC was one of the big shakeouts of undefined behaviour and bugs in our C++ codebase - while making that compiler happy is annoying if you come from Unixy land, it did force us to shed quite a few bad habits and even find several bugs in that endeavor. (And then we could ship the product on Windows, so that was nice.)