Functionality to Delete and manage posts

[CPapadim]

Adding, publishing, and deleting posts is a very manual process right now.

Especially deleting posts is not possible without going directly into the DB when using a dbrepository.

The editor endpoints have a lot of this functionality, but the editor UI is not great for managing posts, it's meant for creating them.

We can expose this functionality by looking at editor.py and exposing those routes in other places (like the posts themselves) on the site. For example, for deleting posts, the route /ajax/editor/delete?path=projects/my_post.kp can do that (though it's not implemented for dbrepository)