Trim whitespace from email addresses

What does this MR do?

This merge request trims whitespace from the email address user input in the Project Member invite form.

Are there points in the code the reviewer needs to double check?

Perhaps this sanitization should apply to other form fields dealing with emails as user IDs. I originally changed this using .strip in member_invited_email in app/mailers/emails/member.rb but it seemed better to have the UI show it correctly. Perhaps both places should be changed?

Why was this MR needed?

In production, a trailing whitespace causes the invitation of a project member by email to fail silently.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• CHANGELOG entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if you do - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

22127