The `LibraryItem` component has been split into a container, responsible
for handling interaction with the storage module, and a component,
responsible for presentation. The component now always takes an
`iconURI` and the logic to load an icon from storage has been moved from
`Library` into `LibraryItem`.

TODO: move animation logic from `SpriteLibrary` into `LibraryItem`. This
should simplify the code quite a bit and might also improve performance.

The basics work but hover animations are broken

Adding relevant EV3/WeDo2 tutorial vid links, fixing up some json, removing some prop validation, etc.

Fixed some margins, added requires/collab library item section, and reminders to make extension/metadata-only.

* Fix all the little RTL layout bugs

- [ ] borders on toolbox and workspace mirror correctly
- [ ] spacing on stage selector is correct
- [ ] stage size icons are mirrored
- [ ] extension library coming soon text is positioned correctly
- [ ] only mirror blocks icon on the tab (others stay right-handed)
- [ ] drop down icon in create variable modal has correct spacing

* FIx RTL backpack header border-radius

* round the bottom corner of paint/sound editors

This makes the editor’s asset panels match the blocks.

Eliminate warnings and errors due to library item text (name and desctiption) being localized components instead of simply a string. Some are not localized (e.g. LEGO EV3), so either string or component is possible.

* WIP tips

* WIP first card stack

* WIP use tips reducer to show things to try

* single card deck similar to mask sequence

* collapse option

* Add zoom card

* WIP tips

* Reorganized to redux

* Add zooming to the gifs

* Blue cards + navigation

* Add tips to new nav bar

* Remove blue

* Update design with icons

* deck updates wip

* Updated card decks

* Add videos to libraries

* Update initial card and clicker preview

* Add backdrop to initial card step.

* WIP use vimeo player instead

* New simple spin deck

* Spin around and say hello decks

* Update button and sub-card styles

* Fix "tips" button in menu bar

* Use move cursor

* Fix cursor

* Use same image for deck preview and library

* Fix cursor again

* Update clicker game deck

* Add videos as single-step decks

* Change tips in menu bar to ? icon

* Change “tips” to “how-tos” in library

* Add help icon to cards

* Update deck library images

* Add drag cover for youtube video to prevent catching mouseup

* add a step to spin deck for clicking control

* Blue bar style updates

* Add step pips

* Update clicker game name to run away

* Fix image padding

* Add change color step to spin deck

* Add start sound step to run away deck

* Update say deck to start with adding a sprite

* Remove package lock

* Remove zooming functionality

* Remove unnecassary prototype changes

* Split up rendering of cards into smaller parts

* Use FormattedMessage for all strings

* Automatic lint fixes

* Almost finished with lint errors!

* Fix more lint errors

* Clean up CSS

* Fix webpack config

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

* Add coming soon extensions to the library

This implements #1074

* don’t call `onSelect` when disabled

thanks @paulkaplan!

* add speech image to coming soon extension