HT @paulkaplan

* Added localization for ‘Make a Block’
* ‘block name’ default text is in scratch-blocks

The changes in `error-step.jsx` were needed because the same id was defined in there and `unavailable_step.jsx`. The scripts to generate the json file for Transifex give an error if the same id is defined in two places. In error step it simply uses the id without redefining default value etc. The alternative would be to add a new messages.jsx file that has the definitions for shared text and include that in both places that use them.

Goes along with https://github.com/LLK/scratch-blocks/pull/1646

- Make stage look more like a tile element and not flust with the stage info width.
- Make the stage select state more apparent

The onMouseUp handler for the menu rerenders the language menu before the select onChange function runs on Firefox. So it resets the language value back to the previous value and the locale doesn’t update. If the languageMenu isopen don’t fire the openlanguageMenu action.

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.

- Resized the next/prev cards and buttons
- Resized the “Remove” and “All Tips” buttons in the nav
- Added hover feedback on next/prev and nav items

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’.

Allow specifying variables as local vs. global. Pass var names from VM to scratch-blocks for checking for conflicts in all sprites when attempting to create a global var.

Fixes #2448 (tab wrapping in Japanese). Also ensures that none of the Sprite info area wraps. Does not address the issue where the sprite info area is too big and pushes the stage info off the screen.