CORE-5832 Initial metadactyl refactor for new schema.

Refactored some old kameleon entities and functions to the new names so that the metadactyl-clj project can compile and run.
CORE-5832 Added middlewares wrapper to swagger calls.

Refactored site-handler wrappers into the middlewares wrapper args.
CORE-5832 Refactored /secured/app-groups endpoint.

Moved this endpoint to /apps/categories with initial swagger documentation, defined under the metadactyl.routes.apps namespace.
Added a metadactyl.routes.params/SecuredQueryParams schema for common secured params.
Refactored metadactyl.app-listings/add-subgroups and format-app-group-hierarchy functions for new db schema.
CORE-5832 Minor refactor.

Renamed the root swagger docs URL to just "/api".
Updated /apps/categories summary.