This ticket implements RFC-300.

Once jointcal has been ported to pybind11 (DM-9187), it will be ready to join the stack in lsst_distrib. This includes the jointcal_cholmod dependency, and the optional testdata_jointcal package (which will be excluded from most installs due to size).

Note to Joshua Hoblitt: We'll need to add testdata_jointcal to the various exclude files once this is ready to go. I'll ping you at that time.