Support geo_point as an object using GeoJSON format

[VijayanB]

Is your feature request related to a problem? Please describe.
geo_point doesn't accept GeoJSON format with type "Point"

Describe the solution you'd like

PUT test-index
{
  "mappings": {
    "properties": {
      "location": {
        "type": "geo_point"
      }
    }
  }
}

PUT test-index/_doc/1
{
  "text": "Support geo_point as GeoJSON Point object",
  "location": { 
    "type": "Point",
    "coordinates": [-88.0, 21.12]
  }
}

Describe alternatives you've considered
Manually convert GeoJSON into previously supported geo_point format

Additional context
Indexing GeoJSON Point as geo_shape is expensive and geo_shape doesn't support all aggregation as geo_point. Users can easily get benefitted by allowing GeoJSON format of type only "Point".

[Yury-Fridlyand]

Tested it on a68733a and it works. I think it could be closed now.
Or we need to add tests and then close.

[heemin32]

Test is added along with the code implementation. We can close this issue.