Weight field for donor

[Zethson]

Saw that hubmap donors also have weights. Not in the official but it's still stored.

@sunnyosun we can of course always store more information and should keep it limited. However, I think that this is still pretty essential information.

[falexwolf]

There will be 50 similar fields. My immediate intuition is that these should all go into the _aux JSON.

[sunnyosun]

There will be 50 similar fields. My immediate intuition is that these should all go into the _aux JSON.

Agreed.

[falexwolf]

We should work out a schema, but my intuition is that the below is a good starting point.

"aux_fields": {
    "weight": 20.5,
    # other fields 
}

This is explicit enough so that we can extend the content of ._aux while exposing these to the user just like regular fields:

Donor.filter(weight__lt=...)
donor.weight  # property that points to the content in the json