DM-27298 the metadata translator added observation_counter and observing_day.
We need to add these to the exposure table in registry.
- Add observing_day as day_obs
- Add observation_counter as seq_num to be compatible with LSSTCam usage (although I do feel that "sequence" is confusing in this context because there are observing sequences that are using a different count).
The visit table can not use the observation_counter since by definition a visit can be one or more exposures that can't share the same counter. observing_day can be added to visit.
There has also been a request to change exposure.name to exposure.obs_id since this is the name used in IVOA's ObsCore schema. "obsID" is a common term so this is not going to be confused with exposure.id.