Extension state does not load from 3.0 project when there are no blocks for that extension in the project

[kchadha]

Expected Behavior

• Project state should be maintained across save and load

Actual Behavior

When using the video extension and turning the video on from the toolbox without dragging any video blocks to any of the sprites' or stage's workspaces, saving and loading the project does not preserve video state.

Steps to Reproduce

1. Create a new project in 3.0
2. Load the video sensing extension; observe that the video turns on
3. Download the project to your computer
4. Reload the page
5. Load the downloaded project from your computer; observe that the video does not turn on and the video sensing extension does not get loaded