* Add mic indicator

* Fix mic indicator position and margin

* Don’t always show indicator, don’t sneaky-enable extension

* Position mic indicator in RTL

* Actually, don’t move indicator in RTL

* Update event name for MIC_LISTENING

* Move mic indicator state into redux

* Move stageSizeToTransform into screen-utils

* Position mic indicator and question at bottom of stage

* Fix pointer events

* JSDOC for stageSizeToTransform

* Pass micIndicator into StageComponent via …props

padding and margin changes to make www project page layout work without hacks; hack to position monitors correctly

This bled into normalizing z-indices for the action menus in the z-index.css. The tooltip id was not unique between action menus for ‘suprise’ and ‘paint’, so `mainTooltipId` was used as a prefix to make them unique.

In addtion to changing the UI color for “mini cards” from motion blue to extensions aqua, this commit also updates the color variable previously known as ‘$pen-primary’ to ‘$extensions-primary’.

- Auditing color CSS and componet CSS to make consistent.
- Made a first pass of changes to increase contrast to elements that previously were problematic

Initial SB2 Import UI (button in preview modal + import modal that can load projects via url). Preliminary validation on url, still needs error handling.

- 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.

This is for https://github.com/LLK/scratch-paint/pull/194, making the selector area smaller on tablet so as to create more space for the paint editor