This PR changes the build script slightly in a way, that vcpkg can more easily handle building the engine. When using the registry, currently the portfile needs to apply a patch before the build completes successfully. With this PR, the patch should be no longer needed.

In particular this PR:

• Moves the toolchain file definition out of the top-level CMakeLists.txt (into the CMakeSettings.json file).
• Removes files that configure into the source directory (i.e. headers of the core project).
• Fixes an issue, that caused glm and DirectX Math to still be linked, even if the dependencies should be disabled.
• Initializes install directories from CMake defaults.