Implement anchor and handle point rendering with the Path Tool (#353)

* Implement Path Tool

* Draw a red rectangle where the first point on the shape is

* Correctly render anchors, handles, and connecting lines

* Fix drain() which can panic

* Refactor frontend messages to work as return values not callbacks

* Reduce the number of unnecessary frontend updates

* Fix stack overflow by using a loop

* Group Document Render calls and put them at the end

* Speed hacks for dirtification

* Add performance

* Bunch folder changed updates

* Add triggers to redraw overlays to movement_handler

* Polish the pixel-perfect rendering of vector manipulators

* Restore scrollbars that were disabled

* Cleanup

* WIP Add shape outline rendering

* Fix compiling

* Add outlines to selected shapes

* Fix outlines rendering over handles and anchors

* Fix dirtification

* Add a comment

* Address code review feedback

* Formatting

* Small tweaks

Co-authored-by: Oliver Davies <oliver@psyfer.io>
Co-authored-by: Dennis Kobert <dennis@kobert.dev>

editor/src/document/document_message_handler.rs

@@ -4,13 +4,14 @@ use graphene::layers::Layer;
 use graphene::{LayerId, Operation as DocumentOperation};
 use log::warn;
 
+use serde::{Deserialize, Serialize};
 use std::collections::VecDeque;
 
 use super::DocumentMessageHandler;
 use crate::consts::DEFAULT_DOCUMENT_NAME;
 
 #[impl_message(Message, Documents)]
-#[derive(PartialEq, Clone, Debug)]
+#[derive(PartialEq, Clone, Debug, Serialize, Deserialize)]
 pub enum DocumentsMessage {
 	CopySelectedLayers,
 	PasteLayers {