Bypass: Extract snr pad recollect to common function
Postcoh tracked the expected time of each pad somewhat differently to bypass, but in the 'recollect' function it boils down to checking what that time is. So postcoh now puts that expected time on each pad like in bypass, though it calculates it differently to bypass. Both call the same function now.
It builds, running a test here: /fred/oz016/tdavies/projects/testing/run_tdavies__rework_pad_alignnment/run2_recollect