Tolerate NaNs in RWD Output

[rajadain]

I noticed some errors in Staging. In case the cause of these was not apparent in the API responses, I took a look under the hood and it seems like the RWD generated output isn't being serialized to JSON. This is a sample output from RWD:

{
  "input_pt": {
    "geometry": {"coordinates": [-75.657663, 39.878647], "type": "Point"},
    "properties": {"ID": 1, "Lat": 39.878647, "Lon": -75.657663},
    "type": "Feature"
  },
  "watershed": {
    "geometry": {
      "coordinates": [
        [
          [-75.657667, 39.878704],
          [-75.657575, 39.878704],
          [-75.657575, 39.878611],
          [-75.657667, 39.878611],
          [-75.657667, 39.878704]
        ]
      ],
      "type": "Polygon"
    },
    "properties": {
      "Area": 0.000080855,
      "AvgOLF": 0,
      "Avgslp": 0.093968607485294,
      "BR": 0,
      "BasinLen": 0,
      "DrnDen": -405268.69086636574,
      "GRIDCODE": 1,
      "RR": NaN,
      "StrLen": -32.768,
      "Strord": -32768
    },
    "type": "Feature"
  }
}

The "RR": NaN is the problem, since NaNs are not allowed in JSON.

Make it so that NaNs are quoted in the output, to tolerate that break and send the rest to the user.