feat: edgeless dnd (#9988)

### Changed
- Support edgelss dnd
- Simplify the drag-handle state

blocksuite/affine/block-surface/src/surface-model.ts

@@ -31,7 +31,8 @@ export const SurfaceBlockSchema = defineBlockSchema({
       'affine:edgeless-text',
     ],
   },
-  transformer: () => new SurfaceBlockTransformer(),
+  transformer: transformerConfigs =>
+    new SurfaceBlockTransformer(transformerConfigs),
   toModel: () => new SurfaceBlockModel(),
 });
 

blocksuite/affine/block-surface/src/surface-transformer.ts

@@ -92,9 +92,18 @@ export class SurfaceBlockTransformer extends BaseBlockTransformer<SurfaceBlockPr
     const snapshot = super.toSnapshot(payload);
     const elementsValue = payload.model.elements.getValue();
     const value: Record<string, unknown> = {};
+    /**
+     * When the selectedElements is defined, only the selected elements will be serialized.
+     */
+    const selectedElements = this.transformerConfigs.get(
+      'selectedElements'
+    ) as Set<string>;
+
     if (elementsValue) {
       elementsValue.forEach((element, key) => {
-        value[key] = this._elementToJSON(element as Y.Map<unknown>);
+        if (selectedElements?.has(key) || !selectedElements) {
+          value[key] = this._elementToJSON(element as Y.Map<unknown>);
+        }
       });
     }
     snapshot.props = {