feat: Add Eraser 🎉 (#4887)

* feat: Add Eraser 🎉

* Eraser working

* remove unused state

* fix

* toggle eraser

* Support deselect with Alt/Option

* rename actionDelete -> actionErase

* Add util isEraserActive

* show eraser in mobile

* render eraser conditionally in mobile

* use selection if eraser in local storage state

* Add sampling to erase accurately

* use pointerDownState

* set eraser to false in AllowedExcalidrawElementTypes

* rename/reword fixes

* don't use updateScene

* handle bound text when erasing

* fix hover state in mobile

* consider all hitElements instead of a single

* code improvements

* revert to select if eraser active and elements selected

* show eraser in zenmode

* erase element when clicked on element while eraser active

* set groupIds to empty when eraser active

* fix test

* remove dragged distance

src/appState.ts

@@ -213,3 +213,9 @@ export const cleanAppStateForExport = (appState: Partial<AppState>) => {
 export const clearAppStateForDatabase = (appState: Partial<AppState>) => {
   return _clearAppStateForStorage(appState, "server");
 };
+
+export const isEraserActive = ({
+  elementType,
+}: {
+  elementType: AppState["elementType"];
+}) => elementType === "eraser";