feat(editor): scaffolding store and view manager in affine (#11840)

Closes: BS-3254

blocksuite/affine/blocks/attachment/src/store.ts

@@ -6,7 +6,7 @@ import { AttachmentBlockSchemaExtension } from '@blocksuite/affine-model';
 
 import { AttachmentBlockNotionHtmlAdapterExtension } from './adapters/notion-html';
 
-export default class AttachmentStoreExtension extends StoreExtensionProvider {
+export class AttachmentStoreExtension extends StoreExtensionProvider {
   override name = 'affine-attachment-block';
 
   override setup(context: StoreExtensionContext) {

blocksuite/affine/blocks/attachment/src/view.ts

@@ -18,7 +18,7 @@ import {
 
 const flavour = AttachmentBlockSchema.model.flavour;
 
-export default class AttachmentViewExtension extends ViewExtensionProvider {
+export class AttachmentViewExtension extends ViewExtensionProvider {
   override name = 'affine-attachment-block';
 
   override effect() {