Fix C++17 builds: (#2192)

- Fix C++17 Visual Studio builds.
- Use C++17 for `windows-2019` builds.
- Removed options for unsupported compiler (MSVC11).
- Removed options, not needed after enabling C++11+ features in gmock/gtest.

.github/workflows/windows.yml

@@ -16,7 +16,7 @@ jobs:
           - os: windows-2016
             standard: 11
           - os: windows-2019
-            standard: 14
+            standard: 17
           - os: windows-2016
             platform: Win32
             build_type: Debug