Add embedable images (#564)

* Add embedable bitmaps

* Initial work on blob urls

* Finish implementing data url

* Fix some bugs

* Rename bitmap to image

* Fix loading image on document load

* Add transform properties for image

* Remove some logging

* Add image dimensions

* Implement system copy and paste

* Fix pasting images

* Fix test

* Address code review

Co-authored-by: Keavon Chambers <keavon@keavon.com>

graphene/src/operation.rs

@@ -53,6 +53,18 @@ pub enum Operation {
 		style: style::PathStyle,
 		size: f64,
 	},
+	AddImage {
+		path: Vec<LayerId>,
+		transform: [f64; 6],
+		insert_index: isize,
+		mime: String,
+		image_data: Vec<u8>,
+	},
+	SetImageBlobUrl {
+		path: Vec<LayerId>,
+		blob_url: String,
+		dimensions: (f64, f64),
+	},
 	SetTextEditability {
 		path: Vec<LayerId>,
 		editable: bool,