GraphQL Extensions

[bkuberek]

Regarding execution of graphql here:

light-graphql-4j/graphql-router/src/main/java/com/networknt/graphql/router/handlers/GraphqlPostHandler.java

Lines 91 to 100 in a74f1a5

	Map<String, Object> result = new HashMap<>();
	if (executionResult.getErrors().size() > 0) {
	result.put(GRAPHQL_RESPONSE_ERROR_KEY, executionResult.getErrors());
	logger.error("Errors: {}", executionResult.getErrors());
	} else {
	result.put(GRAPHQL_RESPONSE_DATA_KEY, executionResult.getData());
	}
	exchange.getResponseHeaders().put(Headers.CONTENT_TYPE, "application/json");
	exchange.setStatusCode(StatusCodes.OK);
	exchange.getResponseSender().send(Config.getInstance().getMapper().writeValueAsString(result));

GraphQL also provides an extensions, perhaps we should add it.

    if (executionResult.getExtensions().size() > 0) {
      result.put("extensions", executionResult.getExtensions());
    }

[stevehu]

@bkuberek Yes. It is a good idea. Could you please submit a PR? Thanks.