Add optional prefix to config for DAG name

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This way, multiple airflow instances can be differentiated within airflow platform. This can help, when using multiple instances for parallel development.

Before merging into dev-branch, please make sure that

• [ ] the CHANGELOG.rst was updated.
• [ ] new and adjusted code is formated using black and isort.
• [ ] the Dataset-version is updated when existing datasets are adjusted.
• [ ] the branch was merged into the continuous-integration/run-everything-over-the-weekend-branch.
• [ ] the workflow is running successful in test mode.
• [ ] the workflow is running successful in Everything mode.