ModuleCommandFactory hierachy should be cleaned up

The distinction between ModuleCommandFactory and ExtendedModuleCommandFactory should go away, and they should be independent interfaces.

The reason for this is cos ModuleCommandFactory is a global component and so should care about creating global commands, i.e. perform GC.

On the other hand ExtendedModuleCommandFactory (which should be renamed) is a cache component and so cares about creating cache specific global components, i.e. invalidate a named region (or cache) in 2LC.