User admin approval - Email when approved

Problem to solve

As part of &4491 , when a user's request to access an instance is approved they should receive an email letting them know.

Intended users

Anyone who requested access!

User experience goal

Proposal

The user should receive an email letting them know they are approved. It should be the an email email similar to the one that is received when a user is created for them by LDAP or by an admin.

Email Title

Welcome to GitLab!

Email Body

Hi (name),

Your GitLab account request has been approved!

Your username is (username)
Your  sign-in page is (instance URL)

Further details

Permissions and Security

Documentation

Availability & Testing

What risks does this change pose to our availability?

This is low risk to GitLab.com availability. However, if for some reason, notification emails do not go out, there could be delay in user signup process to complete causing bad user experience. A test should be added at feature level to ensure emails are sent out upon approval.

What additional test coverage or changes to tests will be needed?

Tests should be added add feature level (or lower) to ensure emails are sent out on approval.

No new end-to-end tests needed.

What does success look like, and how can we measure that?

What is the type of buyer?

Is this a cross-stage feature?

Links / references

Edited by Sanad Liaquat