fixes #1205.

It doesn’t translate any of the text to avoid a case where translation is causing the error, and fails in the error boundary as well.

Add duplicate button. Pass the costume ID to paint (the previous costume ID used matches when duplicate is used.) When switching to the costume tab, open the current costume.

This is required because you can delete the last sound, and without a re
render the tab will continue to render the sound editor, causing an
error.

Improvements to error state: input outline shows with or without focus, and added new error div which shows if there's an error, but goes away if the user starts changing what they had submitted in the input. Removing a lot of code surrounding the tooltip which has now become unnecessary.

Import input now shows error state w/orange border around input and tooltip with static error message.

Initial SB2 Import UI (button in preview modal + import modal that can load projects via url). Preliminary validation on url, still needs error handling.

- Call scrollToCategoryByName('My Blocks') after custom block is created
- Cannot assume custom blocks section will be last category
- May pose issue during localization efforts

Use the same drag threshold as from the blocks. It may need to be dialed
in further, but testing will be needed.