modify to enable custom app names

[emmuhamm]

Description

If full description and testing details are included on a parent issue, please link to that here.
See issue # for details

Otherwise, please include a summary of the change and which issue is fixed (if any).
Include relevant motivation and context, including a target environment and dunedaq version if known.
Also list any dependencies that are required for this change.
Addresses issue #

Please also include instructions for how a reviewer can test your changes.

DUNE-DAQ/drunc#776

Note

The fact that it takes this many changes to get this in means the code is very smelly

This should be the last one to go in before a big refactor of the code

There is a large amount of technical debt here

Type of change

• Documentation (non-breaking change that adds or improves the documentation)
• New feature or enhancement (non-breaking change which adds functionality)
• Optimization (non-breaking change that improves code/performance)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (whatever its nature)

Testing checklist

• Unit tests pass (e.g. dbt-build --unittest)
• Minimal system quicktest passes (pytest -s minimal_system_quick_test.py)
• Full set of integration tests pass (dunedaq_integtest_bundle.sh)
• Python tests pass if applicable (e.g. python -m pytest)
• Pre-commit hooks run successfully if applicable (e.g. pre-commit run --all-files)

Comments here on the testing

Further checks

• Code is commented where needed, particularly in hard-to-understand areas
• Code style is correct (dbt-build --lint, and/or see https://dune-daq-sw.readthedocs.io/en/latest/packages/styleguide/)
• If applicable, new tests have been added or an issue has been opened to tackle that in the future.
  (Indicate issue here: # (issue))