refactor: migrate elements clone from default-tool to extension (#11703)

### Changed
- Add `onRequestElementsClone` action to allow extension to define how to clone gfx elements

blocksuite/affine/blocks/root/src/edgeless/interact-extensions/clone-ext.ts

@@ -0,0 +1,32 @@
+import { getCommonBoundWithRotation } from '@blocksuite/global/gfx';
+import { type GfxModel, InteractivityExtension } from '@blocksuite/std/gfx';
+
+import { createElementsFromClipboardDataCommand } from '../clipboard/command.js';
+import { prepareCloneData } from '../utils/clone-utils.js';
+
+export class AltCloneExtension extends InteractivityExtension {
+  static override key = 'alt-clone';
+
+  override mounted(): void {
+    this.action.onRequestElementsClone(async context => {
+      const { elements: elementsToClone } = context;
+      const snapshot = prepareCloneData(elementsToClone, this.std);
+
+      const bound = getCommonBoundWithRotation(elementsToClone);
+      const [_, { createdElementsPromise }] = this.std.command.exec(
+        createElementsFromClipboardDataCommand,
+        {
+          elementsRawData: snapshot,
+          pasteCenter: bound.center,
+        }
+      );
+
+      if (!createdElementsPromise) return;
+      const { canvasElements, blockModels } = await createdElementsPromise;
+
+      return {
+        elements: [...canvasElements, ...blockModels] as GfxModel[],
+      };
+    });
+  }
+}