Allow update of node pool workload metadata config (#3512) (#2091)

* update of node pool workload metadata

* fix forcenew for nested field as well

* add set to util for forcenewing field schema, move to utils

* add back forcenew for sandbox config

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

.changelog/3512.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+container: Added update support for `node_config.workload_metadata_config` to `google_container_node_pool`
+```