Need way to tag objects seen/interesting/not interesting

[ykwang1]

We need a way to tag sources with a classification/note, and so we can exclude them in the future.

Desired features:
Add column to track last seen date (jd) in ZTF_objects
Add column to ZTF_objects tracking to include objects in LC analysis (will default to SIMBAD_include for objects we haven't previously seen, with option to set to 0 for objects we have seen).
Add column for notes.