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  - Cleaned up internal APIs by deleting unused exports, imports, and outdated code, enhancing maintainability.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

@@ -1,11 +0,0 @@
-import { InlineAdapterExtensions } from './adapters/extensions';
-import { DefaultInlineManagerExtension } from './default-inline-manager';
-import { InlineSpecExtensions } from './inline-spec';
-import { MarkdownExtensions } from './markdown';
-
-export const inlinePresetExtensions = [
-  DefaultInlineManagerExtension,
-  ...MarkdownExtensions,
-  ...InlineSpecExtensions,
-  ...InlineAdapterExtensions,
-];

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

@@ -5,7 +5,6 @@ declare type _GLOBAL_ = typeof RichTextEffects;
 export * from './adapters/extensions';
 export * from './command';
 export * from './default-inline-manager';
-export * from './exts';
 export * from './inline-spec';
 export * from './keymap';
 export * from './markdown';