Returns CDRs for all SIMs, newest first (by end time, then by id), for a window of end times of at most 31 days.
When end_time_to is omitted it defaults to now; when end_time_from is omitted the window is the 31 days up to
end_time_to. A window longer than 31 days is rejected with 400 Bad Request: request older CDRs in consecutive
windows of 31 days or less. All times are UTC.