Feature Request: Option to register filetype specific actions to admin-plugin from other plugins

The page editor has actions for the files in the media area (bottom):

* insert (+)
* view (eye)
* delete (x)

For images the insert button creates: ``

For a pgn file it creates: `[test.pgn](test.pgn)`

Please extend the admin plugin. I would like to register my plugin (javascript part) within the admin plugin to extend the functionality. The `+`-button chould change to a pulldown menu button (optional) like in the editor toolbar if the number of actions is more than one action.

The actions are shown as simple text (list).

As a result each button at a file in the media area could have more than one action. If a user clicks on an action which is added from a plugin, the action from the plugin is triggerd, gets the filename and creates the snippet.

Please provide a simple example on how to use it from a custom plugin - maybe editor-buttons (action `link only` embeds the image without `!` and adds the paramter `?link&display=text`).

Here is a "screenshot" as example:


Since this is for my chess club, i would spend the money to become a baker for 2 $ a month - at least for 2 years.