Remove hardcoded "text" column in _run_classifier_helper function

[sarahyurick]

Our domain, quality, AEGIS, and FineWeb-Edu classifier CLI scripts all accept the --input-text-field parameter but do not use it. Currently, we hardcode these classifiers to use only be able to run on a column called "text", see here.

We need to modify _run_classifier_helper and all subsequent functions to accept a text column.