Tasks for supporting CMP in multi-source applications:

• Review and follow up upstream issues and PR related to supporting CMP in multi-source applications. 
• Create sample CMP and use it in a basic multi-source application
• Verify AVP (argocd vault plugin) works with multi-source application
• Verify various types of multi-source applications work with CMP
  • external helm chart and git repository of value files
  • different branches of a git repository
• Document how multi-source applications work with CMP

Stories have been created for the above tasks under the parent epic (https://issues.redhat.com/browse/GITOPS-4003)