[Gepardec/mega#674] add icon when no bills available

[gattrCh]

Prerequisites: Always create two feature branches (frontend + backend) even if your feature only affects one of them

DEV:

Development

• Acceptance tests by dev [OpenShift feature environment]
  • Moved to "Ready for review"

Review

• Pull-request reviewed + approved (including Code Coverage) by reviewer [GitHub]
• Inform dev after review through MEGA-PR (by reviewer) [Chat Space]
• Version upgrade by dev [GitHub Issue Milestone + maven revision]
• Merge to main by dev [GitHub]
  • Re-add SNAPSHOT to version and push on main [maven revision]
  • Make sure all feature branches are deleted [frontend + backend]
  • Moved to "Ready for deployment"

Deployment

• Integration and Unit tests on main environment passed [Workflow]
• Deployed to the test environment [GitOps Workflow triggered]
  • Moved to "Ready for testing"

PO:

Testing

• Acceptance tests on the test enviroment passed
• Inspected and approved
  • Moved to "Ready for release"