Added new bulk upsert utility.

src/utils/chunk.js

@@ -1,6 +1,6 @@
 'use strict';
 
-function chunk(array, chunkSize) {
+function chunk(array, chunkSize = 1000) {
 	return Array.from({ length: Math.ceil(array.length / chunkSize) })
 		.map((value, index) => array.slice(index * chunkSize, (index * chunkSize) + chunkSize));
 }