[FEATURE] WINTER galactic processing

[robertdstein]

We probably need a dedicated pipeline to process galactic fields. As things stand, we are generating >250k alerts for a single night with a few galactic exposures (as much as 10k per field, >20 times the extragalactic alert rate), so are not able to keep up with data.

We need to rework the pipeline to handle this.

Possible options (not mutually exclusive):

• rb cut (need reliable rb first though)
• Stricter scorr cuts
• Somehow removing stars before alert generation
• Restructure the pipeline to have iterative cuts before e.g naming/history

Fixing non-linearity / using flats should help to some extent, but not clear how much.

In the interim, we should stop generating alerts from the galactic plane.