Resolve "function test grafana dashboards"

What does this MR do?

Add a script that can check on stage/prod, whether all expected dashboards are available. See https://ufz-rdm.atlassian.net/jira/software/c/projects/TSM/boards/105/backlog?selectedIssue=TSM-588

Why is this MR needed?

Because we need to make sure, that the automatically created dashboards are working correctly

How to test this MR?

tbd

⚠️

Do not change the auto-generated Merge commit message or Squash commit message, otherwise the release pipeline fails!

Closes #170 (closed)