Split SharedLibrary functionality out of ClassLoader to ensure one loadLibrary function call

When ClassLoader is used for multiple Manifests, the SharedLibrary is created more than once causing pocoInitializeLibrary to be called more than once from a single application.

The _map in ClassLoader in not common across the different manifest files due to template instantiations. I think a SharedLibraryLoader can be utilized that is used for each ClassLoader.

I have a prototype of this change I am working on and would like to contribute it.