SS-964 Send email confirmation on project access

[j-awada]

Status

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Description

Jira ticket: https://scilifelab.atlassian.net/browse/SS-964

A project owner may give access to their project. Notify the user via email when access is granted.

Types of changes

To indicate the type of change (such as bugfix or new feature), use a github pull request label.

Checklist

If you're unsure about any of the items below, don't hesitate to ask. We're here to help!
This is simply a reminder of what we are going to look for before merging your code.

• This pull request is against develop branch (not applicable for hotfixes)
• I have included a link to the issue on GitHub or JIRA (if any)
• I have included migration files (if there are changes to the model classes)
• I have included, reviewed and executed tests (unit and end2end) to complement my changes
• I have updated the related documentation (if necessary)
• I have added a reviewer for this pull request
• I have added myself as an author for this pull request
• In the case I have modified settings.py, then I have also updated the studio-settings-configmap.yaml file in serve-charts

Further comments

Anything else you think we should know before merging your code!

[churnikov]

We can discuss the suggestions and after that it'll be lgtm