* 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`)

This reverts commit c061f2e2, reversing
changes made to 6e007b1e.

Comments slightly tweaked from kchadha's suggestions

Co-Authored-By: Karishma Chadha <kchadha@media.mit.edu>

Because the video steps get replaced by an image step if offline, we should not show items that would result in having no content