Add CI for CMake on MSVC
Adds CI build for MSVC similar to libxml2!102 (closed). libxml2 is built without dependencies for this.
libxslt binaries are available via artifacts and should therefore fix #40. I've added CI jobs for both x86 and x64 as requested in the issue (x86 is still missing in the libxml2 CI, but could be easily added there as well).
The current CMake binary is downloaded from GitHub as it is not available in the runner, but gets cached for further builds.
Also fixes MinGW-w64 static build (missing quotes in PowerShell).