Automated check for overlapping pulses in a channel

[JelleAalbers]

This is a pathology we encountered during the DAQ test that will probably soon be fixed. However, it would be useful to add an automated check for this to ensure this never recurs. This should just be a simple check for the < condition here: https://github.com/AxFoundation/strax/blob/master/strax/processing/pulse_processing.py#L85, but at the moment implementing it is not a good idea because it would prevent all processing during the DAQ test, until this is fixed :-)

[JelleAalbers]

Straxen now automatically checks for this in records for new data. Hopefully there won't be any overlaps, but if there is an occasional one in a weird circumstance, we'll likely want to handle it gently rather than refusing to even build raw_records. (For now, we crash in records unless the config has check_raw_record_overlaps=False.)