Signing endpoint: Firebase

[AlexanderGeere]

Description

Provide an endpoint for signed urls to firebase, api/sign/firebase?.

GitHub Issue

#1226

Type of Change

• ✅ New feature (non-breaking change which adds functionality)
• ✅ Documentation

How have you tested this?

Tested locally using bugs_testing. The needed environment variables can be found in on xyz_settings/bugs_testing.

Testing Checklist

• ✅ Existing Tests still pass
• ✅ Ran locally on my machine

Code Quality Checklist

• ✅ My code follows the guidelines of XYZ
• ✅ My code has been commented
• ✅ Documentation has been updated
• ✅ New and existing unit tests pass locally with my changes
• ✅ Main has been merged into this PR

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• To see the specific tasks where the Asana app for GitHub is being used, see below:
  • https://app.asana.com/0/0/1207876619030546

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[RobAndrewHurst]

#1474