Including action-menu which was also giving one when the backdrop library opened.
Localize the costume library, I missed it while doing the other libraries.

* Implement GH-830: Add coming soon tooltips

This implements coming soon tooltips for:
* the small stage size
* save, load and language

It also creates the component that can be copied over into the paint editor for use there as well.

Lastly, this does a small refactor on the full screen implementation to include multiple small screen sizes too.

/ht @paulkaplan

Use the de/serialization features of the VM to allow downloading and loading project JSON