ICEES+ API returning 422 ("Unprocessable Entity") for queries that worked previously

[amykglen]

ICEES+ API is returning 422 responses ("Unprocessable Entity") for queries that previously worked.

This can be observed in master with:

pytest -v -s test_ARAX_overlay.py -k test_overlay_exposures

(Look at the warnings generated, which will be printed out with the above command. Note that the pytests are intentionally passing in this situation per #1166.)

I'm wondering if the structure of query graphs ICEES wants changed? (IIRC, the "query graph" they accepted at the endpoint we use deviated a bit from the Reasoner Std API when this integration was coded up.)

If this turns out to be due to an issue on their end, we can close this issue, but seems like we should try to figure out if something needs to be changed on our end.