Major Revision

This PR applies the following major revisions to simplify and streamline the package:

- Moves the Action, Domain, and Responder classes to the top level

- Removes the FormatTypes class and embeds the needed logic in AssetService

- Removes caching behaviors from the AssetService; these are better suited to a something like a build process

- Updates the testing protocol to something more appropriate for *_Bundle packages (taking hints from the *_Kernel testing protocol)