feat: add hand/panning tool (#6141)

* feat: add hand/panning tool

* move hand tool right of tool lock separator

* tweak i18n

* rename `panning` -> `hand`

* toggle between last tool and hand on `H` shortcut

* hide properties sidebar when `hand` active

* revert to rendering HandButton manually due to mobile toolbar

src/data/restore.ts

@@ -55,6 +55,7 @@ export const AllowedExcalidrawActiveTools: Record<
   freedraw: true,
   eraser: false,
   custom: true,
+  hand: true,
 };
 
 export type RestoredDataState = {
@@ -465,7 +466,7 @@ export const restoreAppState = (
           ? nextAppState.activeTool
           : { type: "selection" },
       ),
-      lastActiveToolBeforeEraser: null,
+      lastActiveTool: null,
       locked: nextAppState.activeTool.locked ?? false,
     },
     // Migrates from previous version where appState.zoom was a number