VS: Support Intel Fortran 15 .vfproj generation (#15175)

This version of the Intel Fortran plugin to Visual Studio says:

 please make sure that $(OutDir), $(TargetName) and $(TargetExt)
 property values match the value specified in %(Link.OutputFile)

We must set TargetName and TargetExt in addition to the existing
setting for OutputDirectory.  The settings do not appear to hurt
older versions of Intel Fortran, so set them unconditionally.

Extend the FortranOnly test to cover a corresponding use case by
using the OUTPUT_NAME target property.

Inspired-by: Ian Harvey <Ian.Harvey@megms.com.au>
Merge topic 'vs-intel-15' into next

a128129a VS: Support Intel Fortran 15 .vfproj generation (#15175)