ModelStep should have a 'adds_depends_on' class method

[adam2392]

Describe the feature you'd like
When constructing SageMaker pipelines, I want to construct steps that sequence Training jobs (TrainingStep) and Inference jobs (ModelStep and TransformStep) together. As part of this, I would use add_depends_on from the TrainingStep to allow me to string together tasks. However, we cannot do the same for ModelStep. It has to be passed via the depends_on parameter during initialization.

How would this feature be used? Please describe.

def setup(…):
   model_step = ModelStep(…)
   transform_step = TransformStep(…, model_step…)

model_step.add_depends_on(other_steps)

Describe alternatives you've considered
I am forced to pass in dependencies throughout my abstractions, rather than construct the model_step first, and then add dependencies later.

Additional context
happy to add more details if needed.