Feature (STRINGS-1638) - Add Brakeman, Simplecov, Sonarqube

[BlumMichael]

Purpose:

• Adds brakeman to Github Actions Pipeline
• Adds Sonarqube to Github Actions Pipeline
• Adds simplecov for test-coverage display
• Splits Pipeline in lint and test

Any affected ticket/issue:
https://phrase.atlassian.net/browse/STRINGS-1659

Sonarqube:

Checklist

• Changes are covered by tests

Documentation (mandatory)

• Code has been thoroughly checked for potential security risks.