Add KV Store metrics

apiaddedremoved

This adds kv_store_class_a_operations and kv_store_class_b_operations. These metrics replace object_store_class_a_operations and object_store_class_b_operations. The previously deprecated metrics object_store_read_requests and object_store_write_requests have been removed.

Prior change: JavaScript SDK 2.2.0

Following change: JavaScript SDK 2.2.1