Verify email when changed from user settings

**Is your feature request related to a problem? Please describe.**
I need to avoid user setting a mail they don't own, bypassing the enrollment email verification check (as they can use a verified one during signup and then set an unverified later in the settings)

**Describe the solution you'd like**
Bind a flow to email change in settings, so email can be verified.

**Describe alternatives you've considered**
None, currently my only alternative is to disable email changes :(

**Additional context**
None