Remove the "raise support request in the app" feature

Currently, we have a "Raise a support request" button in the administration which sends an email to our support. We've identified this feature as non-GDPR-proof because:

• We delete emails manually. This opens the door to forgetting to delete emails.

• Sending an email through Confluence implies communicating using the email address, which can be PII.

All such support request had been deleted for now, so we were compliant, but let's remove this feature for safety.