VS: Add an environment variable for the Windows 10 kits directory
Define a CMAKE_WINDOWS_KITS_10_DIR
environment variable to allow
users to tell CMake about a custom Windows 10 SDK directory. We
choose to make this an environment variable rather than a CMake
variable or cache entry because:
-
Using a custom directory also requires custom external MSBuild configuration. Therefore users are already configuring a custom environment.
-
The custom directory must be set consistently in all parts of a build including nested projects. An environment variable avoids requiring users to thread the setting into nested builds.
Fixes: #16743 (closed)