draft of refactor to make custom confirm modal work for upload; need to further edit sb-file-uploader

Add support for custom confirm modal to sb-file-uploader

Show custom confirm modal when confirming project upload

got custom upload refactor of file upload working, and tested failure case

cleaned up debug code, make project file upload work

simplified logic around canceling file upload

removed old sb-file-uploader.jsx; fixed linter errors

reverted two components to use old strings, not shared

(can do that refactor another time)

removed unnecessary confirm container

removed stray comment

moved, updated sb file uploader tests, related project state tests

removed custom modal, to reduce scope of changes

sb file uploader test uses intl

Show alternate logo if GUI is initialized with a different file.

Show or hide the language and file menus.

- Create the scratch renderer earlier in the GUI container/HOC stack
- Delay loading and rendering GUI component until after project assets
  have been fetched

Discovered this while trying to pass other props to the stage wrapper, we were not passing isRTL to the stage wrapper, causing ask/answer bubble to not display the right direction.

The playground now displays this on startup when in Scratch Desktop
simulation mode.

Toward LLK/scratch-www#2296

This allows us to take you to any destination when clicking the logo, or to do something else, or nothing at all.

If no handler is provided, the logo will not be clickable.

use blue creating screen for new projects; revised alert text for copy, remix; saving messages don't dismiss alerts

Fixes 2 related issues:
1. The stage shrinking to 85% based on responsive stylings, which shouldn't happen when embedded in player only
2. When you click "small stage mode" in the editor then switch back to the project page view, it shouldn't show with small stage mode.

Move cloud connection logic into its own HOC and add canUseCloud flag to control whether to show the new cloud variable options in the variable modal.

made remixing, saving as copy states; made project state naming more consistent

changed meaning of canCreateNew to true creation

fixed project-saver-hoc test

removed Remix option from standalone player menu; renamed canSaveAsCopy to canCreateCopy

added parenthesis missing from rebase

fixed create new test

* Connection Modal loads its own data

* Connection does not update flyout status buttons

* WIP moving connection modal into redux

* Lint fix and remove unused prop

* Close modal even if exception on disconnect

don't set redux project title directly from sb uploader; only extract title from .sb2 and .sb3 filenames