R1:7f11e8d7401e

Improve handling of email verification and "activated" accounts

Summary:
Small step forward which improves existing stuff or lays groudwork for future stuff:

- Currently, to check for email verification, we have to single-query the email address on every page. Instead, denoramlize it into the user object.
- Migrate all the existing users.
- When the user verifies an email, mark them as `isEmailVerified` if the email is their primary email.
- Just make the checks look at the…