WIP: Locate same named method, instances and classes across domains

This feature allows the UI to display a list of overridden instances
and methods from different domains. The functions return an array of classes or instances or methods ordered based on the domain priority. The UI should be
able to guide the end user to the highest priority instances and methods
@mkanoor All the get_homonymic_* methods here share the same pattern and we should be able to DRY these up.  Maybe create the base method in MiqAeDatastore and have a method in each model that just supplies the required class (::MiqAeClass/::MiqAeMethod/::MiqAeInstance) and the options needed for the class version.

Also, I think including a qualifier like 'methods' in the method name is redundant since it is already being called from the MiqAeMethod model.  The method name could be the same across all the classes.