Do not block transition in EntityWorkflow when the user is member of a dest user group

- refactor EntityWorkflowGuardTransition + tests
- allow to find easily user within userGroup by adding a dedicated method to UserGroup::contains

src/Bundle/ChillMainBundle/Workflow/EventSubscriber/EntityWorkflowGuardTransition.php

@@ -87,6 +87,17 @@ class EntityWorkflowGuardTransition implements EventSubscriberInterface
             return;
         }
 
+        if (!$user instanceof User) {
+            $event->addTransitionBlocker(
+                new TransitionBlocker(
+                    'workflow.Only regular user can apply a transition',
+                    '04fb4f76-7c0e-11ef-afc3-877bad7b0fe7'
+                )
+            );
+
+            return;
+        }
+
         // for users
         if (!in_array('only-dest', $systemTransitions, true)) {
             $event->addTransitionBlocker(
@@ -108,6 +119,13 @@ class EntityWorkflowGuardTransition implements EventSubscriberInterface
                 return;
             }
 
+            // we give a second chance, searching for the presence of the user within userGroups
+            foreach ($entityWorkflow->getCurrentStep()->getDestUserGroups() as $userGroup) {
+                if ($userGroup->contains($user)) {
+                    return;
+                }
+            }
+
             $event->addTransitionBlocker(new TransitionBlocker(
                 'workflow.You are not allowed to apply a transition on this workflow. Only those users are allowed: %users%',
                 'f3eeb57c-7532-11ec-9495-e7942a2ac7bc',