BUG FIX: ensure matching of args in aggregate_channels and ChannelAggregationRecording

[chrishalcrow]

Fixes #3825.

In #3767, we decided to deprecate recording_list in favor or recording_list_or_dict, now that aggregate_channels can accept dicts. I did the deprecation at the "user level" by putting it in aggregate_channels and only allowing ChannelAggregationRecording to accept recording_list_or_dict. This creates a bug since the saving functions use the args from aggregate_channels but the load-from-provenance functions use the args from ChannelAggregationRecording. So e.g. sorting fails in #3825.

This PR fixes the bug by unifying the arguments in the function and class.

Minimal version of #3825 bug:

import spikeinterface.full as si

rec, _ = si.generate_ground_truth_recording(num_channels=2)

rec.set_property("group", [0,1])
list_of_recs = list(rec.split_by('group').values())
agg_rec = si.aggregate_channels(list_of_recs)

agg_rec.save_to_folder(folder='my_rec')
loaded_rec = si.load("my_rec/provenance.pkl", base_folder="my_rec")

[zm711]

Nice Chris. And a test added! Looks good to me at least :)