Decouple node graph execution (#1209)

* Decouple node graph execution from the main loop

* Trigger document Render + Layer updates after the graph evaluation

editor/src/dispatcher.rs

@@ -205,6 +205,10 @@ impl Dispatcher {
 		list
 	}
 
+	pub fn poll_node_graph_evaluation(&mut self, responses: &mut VecDeque<Message>) {
+		self.message_handlers.portfolio_message_handler.poll_node_graph_evaluation(responses);
+	}
+
 	/// Create the tree structure for logging the messages as a tree
 	fn create_indents(queues: &[VecDeque<Message>]) -> String {
 		String::from_iter(queues.iter().enumerate().skip(1).map(|(index, queue)| {