Users allowed to modify their email address after logged in

[robert-dm]

As an user, Mentor, Mentee, Partner, I should be allowed to Edit Profile and have the ability to modify my email address, so that I can start using another email address moving forward.
It will require

• user able to see email address currently used and enter a new one email address to switch
• new email to be registered in firebase
• new email to replace old email in the database for this user
• notification email sent using sendgrid so that the user knows it has been done successfully
• all must support multi language
• unit tests to be added for this new feature