Feature: Action System (#298)

* Add Action System

- Add keyboard test
- Add context menu label
- Add PanelComponent

* Show context menu items based on actions

* Add render action feature

- Replace bringForward etc buttons with action manager render functions

* Move all property changes and canvas into actions

* Remove unnecessary functions and add forgotten force update when elements array change

* Extract export operations into actions

* Add elements and app state as arguments to `keyTest` function

* Add key priorities

- Sort actions by key priority when handling key presses

* Extract copy/paste styles

* Add Context Menu Item order

- Sort context menu items based on menu item order parameter

* Remove unnecessary functions from App component

src/actions/index.ts

@@ -0,0 +1,33 @@
+export { ActionManager } from "./manager";
+export { actionDeleteSelected } from "./actionDeleteSelected";
+export {
+  actionBringForward,
+  actionBringToFront,
+  actionSendBackward,
+  actionSendToBack
+} from "./actionZindex";
+export { actionSelectAll } from "./actionSelectAll";
+export {
+  actionChangeStrokeColor,
+  actionChangeBackgroundColor,
+  actionChangeStrokeWidth,
+  actionChangeFillStyle,
+  actionChangeSloppiness,
+  actionChangeOpacity,
+  actionChangeFontSize,
+  actionChangeFontFamily
+} from "./actionProperties";
+
+export {
+  actionChangeViewBackgroundColor,
+  actionClearCanvas
+} from "./actionCanvas";
+
+export {
+  actionChangeProjectName,
+  actionChangeExportBackground,
+  actionSaveScene,
+  actionLoadScene
+} from "./actionExport";
+
+export { actionCopyStyles, actionPasteStyles } from "./actionStyles";