Refactor set of cluster scoped handlers

Problem: Cluster scoped gc was taking significantly longer to complete
than before 7387aa5. This was due to a large number of list calls and
the time needed to iterate over them.

Solution: Instead of requesting every type than Rancher uses, a
seperate map appended to when a cluster scoped handler
is created. The full map of all GroupVersionResources is kept as a
fallback for the use case where user controllers may exist on another
host other than the current leader.

generator/controller_template.go

@@ -157,6 +157,7 @@ func (c *{{.schema.ID}}Controller) AddHandler(ctx context.Context, name string,
 }
 
 func (c *{{.schema.ID}}Controller) AddClusterScopedHandler(ctx context.Context, name, cluster string, handler {{.schema.CodeName}}HandlerFunc) {
+	resource.PutClusterScoped({{.schema.CodeName}}GroupVersionResource)
 	c.GenericController.AddHandler(ctx, name, func(key string, obj interface{}) (interface{}, error) {
 		if obj == nil {
 			return handler(key, nil)