Windows: Option to add SOVERSION to DLL names

With VulkanSceneGraph there is a request to create versioned shared libraries with MinGW by adding a SOVERSION-based suffix to the output filename, such as is common with MinGW packages on an openSUSE distribution [see related thread] (https://github.com/vsg-dev/VulkanSceneGraph/pull/663#issuecomment-1353206334).

The vsg maintainer pointed out that this would be better solved in cmake after all: https://github.com/vsg-dev/VulkanSceneGraph/pull/663#issuecomment-1353024214

I assume other CMake users have the same problem on MinGW/Windows, so maybe CMake itself could provide the behavior instead of replicating it in our local CMake scripts.