[FEATURE] Sequential execution for local pipeline

[gabrielmbmb]

Description

As mentioned by @alvarobartt and Ellamind team, it would be nice to have a sequential model for executing the pipeline, in which no multiprocessing & batching is used.

The idea would be to load each step, process all the data, unload the step, load the next step, ...

[bjoernpl]

Just adding here that a goal of this would be to enable proper debugging within steps/tasks in the pipeline. Thanks for picking this up! :)