styling for title field; correct input target in tests; make download filename safer with default, max length; in playground index, correctly pass props through to gui container

Unfortunately I couldn't do the same with loading projects, since the presence of the component (necessitating the menu to be open) allows the actual upload from file to work, since it needs the FileInput component to be present, so it can emit a change event.  We should revisit

Overlay a transparent `select` over the language icon. When a user clicks there the options pops up. There’s no styling of the options, other than font and font size.

This reverts commit 1c20d6db, reversing
changes made to 2f1cce93.

Note: the coming soon tooltip positions are calculated by react-tooltip, and they do not handle RTL.

HT @paulkaplan

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.

* refactor LanguageSelector to reuse MenuBarMenu
* localize aria-labels on MenuBar

Allows the language selection menu to be active if `?enable=language` is in the URL, otherwise shows a ‘coming soon’ tooltip. This can also land on a branch if we don’t want that available on preview.

- language menu opens if the globe is clicked
- language menu closes if mouse is clicked anywhere outside the language selector
- language list is imported from scratch-l10n
- current locale is updated if another language is selected (i.e. the current language selected changes)

Not in this PR:
- styling of language selector
- actually changing the messages!

* 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...

There's a subtle difference in behavior between mouseup and click. Using mouseup allows you to close the menu by clicking its opener item.