Add Polygon Type To Schema / PolygonContain to Query (#3944)

* Added type polygon to schema

* refactoring and more tests

* fix tests

* update test and transform

* add support for polygonContains

* fix transform.mongoObjectToParseObject test

* add indexes for polygon

* index test

* postgres test fix

* remove invalid loop test

* add invalid loop test

* nit

src/Adapters/Storage/Mongo/MongoSchemaCollection.js

@@ -25,6 +25,7 @@ function mongoFieldToParseSchemaField(type) {
   case 'geopoint': return {type: 'GeoPoint'};
   case 'file':     return {type: 'File'};
   case 'bytes':    return {type: 'Bytes'};
+  case 'polygon':  return {type: 'Polygon'};
   }
 }
 
@@ -98,6 +99,7 @@ function parseFieldTypeToMongoFieldType({ type, targetClass }) {
   case 'GeoPoint': return 'geopoint';
   case 'File':     return 'file';
   case 'Bytes':    return 'bytes';
+  case 'Polygon':  return 'polygon';
   }
 }