Delayed postprocessing timeout logic for 5.4.x line

[alessandrothea]

Description

Mirror PR to #104

• Items can get stuck in buffer without getting postprocessed if no new items arrive. To fix this, we implemented a timeout logic that takes into consideration how many timeouts occurred since an item has been waiting to get processed.
• Trigger has to define a policy on what to do in case of a timeout. For this, we introduced a new function in DataHandlingModel that will be overriden by TriggerDataHandlingModel. The function is called by postprocess scheduler.

Addresses issue DUNE-DAQ/trigger#416

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

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 (daqsystemtest_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))

[ShyamB97]

Changes were tested with the BDE and TDE for a short duration run without issue. LGTM