A complete rewrite of OpcodeLabels. Instead of function, it’s a class that maintains a current translator function, and updates the opcode labelFn for each opcode when a new translator function is set. Add function `getLabel` to return the object with `category` and `labelFn` based on the opcode.

Set intl.formatMessage as the translator function in MonitorList. It has access to the intl object, and wraps all monitors.

* Translate "(empty)" and "length {value.length}"
* Use FormattedMessage

Removing highlight when hovering over alert close button after one closes, other minor styling fixes.

and other small sprite and costume library updates

* 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

Move the labels above the inputs for languages that don’t fix in the width of the sprite-info pane.

Because of the different widths of everything I left aligned them.

Examples,
Abkhaz, Catalan, Greek.

renamed the `rtl-locales` lib file as `locale-utils` as  it’s doing more than rtl now. RTL should probably move into the scratch-l10n repo, but should the `wide-locales` setting? That seems like something that is gui specific. I don’t like having to hard code the specific languages that don’t fit, but there didn’t seem to be a better way to handle it right now.

Moving click handling to alert component from container in order to handle index correctly.  Removed AlertsComponent and added new AlertComponent.

* added account navigation menu, copied and adapted from www

* fixed css

* support for login menu, registration menu from www

* Dropdown replaced with MenuBarMenu, override www css in menus

* render and style login dropdown via function from www

* moved menu styling from menu itself to menu bar

* refactoring menu components and containers

* refactor and restyle account nav menu

* cleaned up cruft and css per rschamp's review of PR 3070

For use from `scratch-desktop` and maybe other places...