refactor(editor): cleanup dead code (#12281)

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

- **Refactor**
  - Streamlined and consolidated block and inline extension exports by removing multiple block-spec and inline extension arrays from public APIs.
  - Reduced exported constants, types, and utility functions related to various block and embed features.
  - Simplified the codebase by removing deprecated type guards, adapter extensions, and redundant extension groupings.
- **Chores**
  - Cleaned up internal APIs by deleting unused exports, imports, and outdated code, enhancing maintainability.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/blocks/surface/src/index.ts

@@ -28,10 +28,6 @@ export {
   SurfaceBlockSchema,
   SurfaceBlockSchemaExtension,
 } from './surface-model.js';
-export {
-  EdgelessSurfaceBlockSpec,
-  PageSurfaceBlockSpec,
-} from './surface-spec.js';
 export { SurfaceBlockTransformer } from './surface-transformer.js';
 export * from './tool/default-tool.js';
 export {