[feature] Change segments file from parquet to csv

[WilliamCappelletti]

Is your feature request related to a problem? Please describe.

Parquet is not human readable

Describe the solution you'd like

Moving to csv or some other "excel" compatible format would allow for quicker human inspection.

Describe alternatives you've considered

Adding one intermediate file from which we compute the parquet would allow to have human-readable format and no zero lines (cfr other issue), while keeping the same implementation for the pipeline