Prevent removing all verified information

[kynan]

• When signing up via a network, it's currently possible to remove the connection to that network, effectively disabling sign in (password reset works though).
• It's currently possible to remove all verified emails, although sign in is still possible via that email.

[magitam]

For this particular error, if the 'connection' to a network is removed, then before it can be removed, we should 'verify' an email address, and have the user generate/create a password to be associated with the email address, before they can remove the 'social' connection, that was used to create the account