Automate paid non-invited users#497

Current:

• Users must be invited users for them to be upgraded.

Expected:

• If a user has upgraded, any user who has private access to the wiki and signs in is upgraded to paid.

Short term fix:

• Anyone using an email with the custom domain of someone who is paid, who then signs in, is automatically upgraded

There was an additional case where a user signed up, upgraded and that account was not upgraded.