Shorten UpdateNodeLabelsAndRecordEvents function in nmc_reconciler.go

Today, the UpdateNodeLabelsAndRecordEvents function has around 100 lines of code. This commit aims to enhance its readability and maintainability by using helper functions, thereby reducing its total length.
Additionally, adding unit tests that covers the new helper functions.

cmd/manager/main.go

@@ -121,6 +121,7 @@ func main() {
 	buildHelperAPI := build.NewHelper()
 	nodeAPI := node.NewNode(client)
 	kernelAPI := module.NewKernelMapper(buildHelperAPI, sign.NewSignerHelper())
+	lph := controllers.NewLabelPreparationHelper()
 
 	dpc := controllers.NewDevicePluginReconciler(
 		client,
@@ -149,7 +150,7 @@ func main() {
 
 	eventRecorder := mgr.GetEventRecorderFor("kmm")
 
-	if err = controllers.NewNMCReconciler(client, scheme, workerImage, &cfg.Worker, eventRecorder, nodeAPI).SetupWithManager(ctx, mgr); err != nil {
+	if err = controllers.NewNMCReconciler(client, scheme, workerImage, &cfg.Worker, eventRecorder, nodeAPI, lph).SetupWithManager(ctx, mgr); err != nil {
 		cmd.FatalError(setupLogger, err, "unable to create controller", "name", controllers.NodeModulesConfigReconcilerName)
 	}