Restore missing triggers between steps
fixes #2530

it:
- reverts #2489
- adds the missing triggering step
- adds a check when creating the processing graph, to ensure all the config- and dataset-level steps have at least one triggering step of the same level, to handle the case where we couldn't get the configs or the splits.


Restore missing triggers between steps: fixes #2530

it:
- reverts #2489
- adds the missing triggering step
- adds a check when creating the processing graph, to ensure all the config- and dataset-level steps have at least one triggering step of the same level, to handle the case where we couldn't get the configs or the splits.

