Add option to create a new menu from the CM

The Essentials menu component lets you add a menu wherever you want (just add the component to a container). But: you can only add a menu (by name even) that must already exist in the workspace.

It would be really convenient if:

• users can choose from a list of available menus
• create a new menu altogether

This may need a new function in the CM itself, I'm not sure.