Update the actions registering in fort

Foreman tasks provides a way how to register the paths with actions.
This way, things like actions autoloading should work.

Also, the actions are moved into `app/lib` to follow the layout
Katello uses.
Rename the actions to follow the names of the files
Switch from `Fort::Actions` to `Actions::Fort`

To follow the layout from the Katello lib
Merge pull request #3759 from iNecas/cv-rework-fort-layout

Update the actions registering in fort