Add new option for [General] process_new_segments_from option, 'segment_last_edit_time'. New option sets beginning of segments archiving from last edit time (or created time if it is found). Includes tests.

When segment creation time (or just earliest archive date) is greater than end date of requested range to archive, use end date as override for start of archiving request range.

Fixes #7223, add new INI option [General] process_new_segments_from that controls the start date of archiving for segments that have not been archived before. If a creation date cannot be found, now is used.