Path Tool: Implement anchor point dragging (#451)

* #82 path-tool: WIP selecting control point working

* Fix bug where duplication with Ctrl+D doesn't properly duplicate (#423)

* bug fix: duplication didn't properly duplicate

* cargo fmt

* changed the formatting slightly for readability

* Small cleanups, changed color of handles upon selection

* Fix changes from merge

* Remove duplicate anchor points on top of one another

* Fix possible issues with thumbnails not being updated from Graphene operations

* path-tool: attempt to move control points on click

* Add dragging for control points

* Editing shape anchors functional. Handles next.

* Comment cleanup & slight cleanup of closest_anchor(..)

* Removing conflict with master

* Tiny code tweaks

Co-authored-by: Keavon Chambers <keavon@keavon.com>
Co-authored-by: caleb <56044292+caleb-ad@users.noreply.github.com>
Co-authored-by: otdavies <oliver@psyfer.io>
Co-authored-by: Dennis <dennis@kobert.dev>

graphene/src/operation.rs

@@ -65,6 +65,7 @@ pub enum Operation {
 		path: Vec<LayerId>,
 		bez_path: kurbo::BezPath,
 		style: style::PathStyle,
+		closed: bool,
 	},
 	DeleteLayer {
 		path: Vec<LayerId>,
@@ -96,6 +97,10 @@ pub enum Operation {
 		path: Vec<LayerId>,
 		transform: [f64; 6],
 	},
+	SetShapePath {
+		path: Vec<LayerId>,
+		bez_path: kurbo::BezPath,
+	},
 	SetShapePathInViewport {
 		path: Vec<LayerId>,
 		bez_path: kurbo::BezPath,