[swagger-parser-v2-converter] vendor extensions from body params not copied to RequestBody

[wsalembi]

Vendor extensions defined on body params are not copied over to the OpenAPI v3 RequestBody

Example:

{
            "in": "body",
            "name": "body",
            "required": true,
            "schema": {
              "$ref": "#/definitions/Person"
            },
            "x-log-mapping": {
              "$.name": "LAST_NAME",
              "$.firstName": "FIRST_NAME"
            }
}