Add a system to keep track of email notifications

[manuboojuk]

Describe the solution you'd like
Add a system to keep track of the email notifications that the user has setup. This would let the user edit and delete their notifications.

Describe Possible Solutions
This would probably require using the db to store notification information and then change it later on.

Additional context
This issue is for the winter 2022 upgrade of Viaplanner. Emailing functionality also depends on Shibboleth working which is another issue.