* Updates to preview modal for release

* Design tweaks and remove import modal

* Resolve issues with tests

* Copy edits HT Eric

* Resolve lint issue with integration test

* One more change to the disclaimer language

* Add line break

They're spammy — happy to put this back but they were unhelpful while fixing tests IMO.

- export image and sounds in dist/static/assets
- rename main export (`scratch-gui.js`, not `index.js`)
- move project-loader-hoc back to lib (VM doesn’t load properly without it)

Allow intl to be passed in to GUI as a prop (rather than having to be already in the store)

Pages no longer reload if you hit the same hash URL twice

Resolves https://github.com/LLK/scratch-gui/issues/1713

Add a jest unit test for making sure the number is rendered out when
provided and not when not provided.

Fix integration tests for the recent chrome stable update

* Change default variable name to 'my variable'. 

* Update integration test to look for 'my variable'. Re GH-1162

* Resolve issue with space in integration test

- implements welcome to the preview modal, and unsupported browser modal.
- will need assets updated in Jan.

* 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.