Build a simple, do-nothing VS 7.1 MFC wizard generated app
with CMake.

Build it two different ways via ExternalProject, one with
CMAKE_MFC_FLAG set to 1 for linking to MFC statically, and
one with CMAKE_MFC_FLAG set to 2 for linking to the shared
MFC dlls.

Validate that the install tree of the static build has only
one *.exe file in it and nothing else. Also validate that the
install tree of the shared library build has multiple files in
it (no less than 3) and that they are only of the expected types
*.exe, *.dll and *.manifest.

This commit does not address the issue reported in #11213,
it merely adds a test that may be used to show that the
bug report is valid. After this commit, the MFC test should
fail on any dashboard machines that have MSVC defined, but
cannot build an MFC app. We can then analyze that failure
data as input to solving the issue.