Including sprites, backdrops, costumes and sounds inputs

I needed to update the player css because the editor side wasn't large enough to be useable.

Update project changes test to test a project change that should actually emit a change event. Clicking on blocks should not emit a project changed event.

I know we will want to change this eventually, so I added comments about that. But the next commit originally contained an inadvertent change to this functionality, so I wanted to add an integration test so that when we do change it, we

It looks like an "test.only" was left in on one of these tests by mistake.

This should have happened a long time ago, but the Fastly config prevented it

Expand on the backdrop integration test to make sure this is documented/tested behavior

* Add test for Scratch Link unavailable error modal

* update vm