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  - Cleaned up internal APIs by deleting unused exports, imports, and outdated code, enhancing maintainability.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/inlines/reference/src/exts.ts

@@ -1,11 +0,0 @@
-import type { ExtensionType } from '@blocksuite/store';
-
-import { ReferenceInlineSpecExtension } from './inline-spec';
-import { RefNodeSlotsExtension } from './reference-node';
-import { referenceNodeToolbar } from './toolbar';
-
-export const inlineReferenceExtensions: ExtensionType[] = [
-  referenceNodeToolbar,
-  ReferenceInlineSpecExtension,
-  RefNodeSlotsExtension,
-];

blocksuite/affine/inlines/reference/src/index.ts

@@ -1,5 +1,4 @@
 export * from './adapters';
-export * from './exts';
 export * from './inline-spec';
 export * from './reference-node';
 export * from './toolbar';