Refactor UI templates to not depend on the UI

The classes for the UI templates – both the original app/gdg/policy and the new gsh ones – were written to only be usable from the UI. This means that they can't be called from GSH or from WS, without creating mock HTTPRequest and HTTPSession containers. It also makes it harder to write unit tests. The classes have been added to the edu.internet2.middleware.grouper.grouperUi.beans.ui package, even though they are not beans. This makes it harder to identify which classes are related to the template functionality, since they are mixed in with container bean classes that were originally meant to be for jsp templates.

See also GRP-3041 Make the Template Feature available in the WS API