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

* add scratchLogo as default for logo prop
* prefer `{featureAllowed && (<Component />)} over ternary operator with a null ‘else’
* renamed `handleSaveToComputer` as `getSaveToComputerHandler` to more clearly represent what it’s doing (returning a function to be the handler)
* renamed the parameter that is the function to handle clicking on the load project menu item (also updated the comments in `SBFileUploader`)

Too much traffic, not enough value. Leaving stuff having to do with tips library/tutorial card navigation as well as hardware extension connectivity, as those help us find issues with Scratch.

Selenium loads the playground using the file:// protocol, where history.replaceState throws an error

This only shows when you are on a project that is SHOWING_WITHOUT_ID and has changes. This is only the case when logged out, or in the desktop editor.

responding to canSave without needing canSaveNew prop
removed canSaveNew
added default for onUpdateProjectId
removed conflict files erroneously added
don't pass down onError
got tests passing
better creating and saving logic and names

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

stripped title handling from sb file uploader
updated more projectState related names
simplified hash-parser-hoc logic slightly

load new project, both json and title; set title on file load; draft of code to fetch title from api

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