CMake: Bump minimum required

@filip-stenstrom it should be ok now: I added a msvc CI job

Great. Our internal CI is failing though, but on the component testing, i.e. make test_installation. It's run after the unit testing. Below is what I'm seeing in the logs.

The FMIL_HOME is using the installation built from the Makefile install target.
The output shows that msvc_md_debug fails, but it's the same for msvc_md and msvc_mt.

$ make test CONFIG_FILE=build/config/msvc_md_debug

<build installation>
<unit tests etc...>

set -eu; \
    cd Test/test_installation; \
    rm -rf build && mkdir -p build; \
    cd build; \
    cmake -DFMIL_HOME=/r/.../fmi-library/install_msvc_md_debug -G "Visual Studio 15 2017 Win64" ..; \
    cmake --build .; \
    ctest 
-- The C compiler identification is MSVC 19.14.26429.4
-- The CXX compiler identification is MSVC 19.14.26429.4
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: C:/Program Files (x86)/Microsoft Visual Studio/2017/Professional/VC/Tools/MSVC/14.14.26428/bin/Hostx86/x64/cl.exe - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: C:/Program Files (x86)/Microsoft Visual Studio/2017/Professional/VC/Tools/MSVC/14.14.26428/bin/Hostx86/x64/cl.exe - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- FMIL_HOME: R:/.../fmi-library/install_msvc_md_debug
-- Configuring done
-- Generating done
-- Build files have been written to: R:/.../fmi-library/Test/test_installation/build
Microsoft (R) Build Engine version 15.7.179.6572 for .NET Framework
Copyright (C) Microsoft Corporation. All rights reserved.

  Checking Build System
  Building Custom Rule R:/.../fmi-library/Test/test_installation/CMakeLists.txt
  main.c
main.obj : error LNK2019: unresolved external symbol jm_get_default_callbacks referenced in function main [R:\...\fmi-library\Test\test_installation\build\main.vcxproj]
main.obj : error LNK2019: unresolved external symbol fmi_import_allocate_context referenced in function main [R:\...\fmi-library\Test\test_installation\build\main.vcxproj]
main.obj : error LNK2019: unresolved external symbol fmi_import_free_context referenced in function main [R:\...\fmi-library\Test\test_installation\build\main.vcxproj]
R:\...\fmi-library\Test\test_installation\build\Debug\main.exe : fatal error LNK1120: 3 unresolved externals [R:\...\fmi-library\Test\test_installation\build\main.vcxproj]
  Building Custom Rule R:/.../fmi-library/Test/test_installation/CMakeLists.txt
  main.c
  main_shared.vcxproj -> R:\...\fmi-library\Test\test_installation\build\Debug\main_shared.exe
make: *** [test_installation] Error 1

modelon-community / fmi-library

CMake: Bump minimum required #115