Intel: Expose VS plugin version to CMake language

Lookup the Intel VS plugin version on construction of the VS global
generator and compute from it the .vfproj format version number.  Add it
as a CMAKE_VS_INTEL_Fortran_PROJECT_VERSION platform definition.
Intel: Fix .vfproj format version during compiler id detection

Use CMAKE_VS_INTEL_Fortran_PROJECT_VERSION to set the .vfproj format
version.
Merge topic 'vs-intel-compiler' into next

4483fd9 Intel: Fix .vfproj format version during compiler id detection
519ab70 Intel: Expose VS plugin version to CMake language