[Messenger example] create new group

xx-messenger example

• Add groups list screen
• Add new group screen
• Implement creating new group

Examples/xx-messenger/Sources/GroupsFeature/GroupsComponent.swift

@@ -62,6 +62,10 @@ public struct GroupsComponent: ReducerProtocol {
         state.newGroup = nil
         return .none
 
+      case .newGroup(.didFinish):
+        state.newGroup = nil
+        return .none
+
       case .newGroup(_):
         return .none
       }