Allows users to specify a note when reporting phishing emails

[kiwiz]

This change only covers necessary frontend changes - the dashboard stills needs to be updated to support this. See #21.

There are some other changes in this PR that may be contentious:

• Enabled IsThisLegit on inbox.google.com
  • Updated button (to a hook icon) so it shows up better in Inbox

[jordan-wright]

This looks fantastic! Thanks for sending this over. I'll review this later this week and, if all looks good, will merge it into a branch. That way, I can work on the dashboard side of things to at least get the notes stored properly before merging into master.

Thanks again for sending this over! Great stuff!

[jordan-wright]

I'm going to go ahead and merge this into the 21-add-notes branch so I can start work on the backend stuff. I know the dashboard can be a bit less-clean to navigate, so when I have the work complete I'll tag you in case you're interested to see the process of adding stuff to the dashboard.

In terms of what this will look like for admins, I'm likely going to add comment boxes (very similar to those seen here in the Github issues) directly into the event timeline.

[kiwiz]

✌️ Sgtm!