CMAKE_VS_SDK_EXTERNAL_INCLUDE_DIRECTORIES

As I’m sure the CMake team knows 16.10 introduced the new external functionality changes.

As a result we had to ammend some of our code as well. Like so:

set(CMAKE_VS_SDK_INCLUDE_DIRECTORIES ${FOOBAR_DK_INCLUDE_DIRECTORIES})
# As of VS 2019 16.10 there is a new field.
set(CMAKE_VS_GLOBALS "ExternalIncludePath=${CMAKE_VS_SDK_INCLUDE_DIRECTORIES }")

Instead of manipulating CMAKE_VS_GLOBALS. Ideally we get a new variable to express this better. Just like the other existing SDK include variables.

The initial MR for this is here: https://gitlab.kitware.com/cmake/cmake/-/merge_requests/4766

See also CMake Issue 17904 and CMake Issue 22163