Extension alert toasts

[grod220]

At the moment, we do not have a way to communicate errors within the extension. Quite frequently, we've asked users to do right click -> inspect -> console to see if there is anything there. It's made troubleshooting quite a challenge. Though, we do have one element that does communicate error states and gives users an indication something is wrong, the block sync bar:

However, #963 has illuminated the need to be able to trigger some type of toast or popup or indicator if there is an issue the user should be flagged about. Possible design direction:

Some ideas:

• Create a high level component that catches all errors that bubble up and put it in a toast
• Expose an API that allows for manual toast triggering (say in a try/catch)
• Consider having a high level service worker error catcher that can propagate errors back to the extension for toast triggering