feat(editor): slash menu and toolbar widget extensions (#12002)

Closes: BS-3226
Closes: BS-3227
Closes: BS-3228
Closes: BS-3229

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

- **New Features**
  - Introduced new view extensions for remote selection, scroll anchoring, slash menu, and toolbar widgets, enhancing customization and integration capabilities.

- **Refactor**
  - Updated export paths and module structure for widget-related packages to improve modularity and accessibility.
  - Reorganized internal dependencies and removed redundant widget imports from core block packages.
  - Refactored edgeless-related widgets and components to use a standardized scope interface for improved context and state management.
  - Centralized graphics controller access and slot management through standardized context objects.

- **Chores**
  - Added and updated dependencies to streamline extension loading and workspace management.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/blocks/root/package.json

@@ -34,8 +34,6 @@
     "@blocksuite/affine-rich-text": "workspace:*",
     "@blocksuite/affine-shared": "workspace:*",
     "@blocksuite/affine-widget-edgeless-toolbar": "workspace:*",
-    "@blocksuite/affine-widget-remote-selection": "workspace:*",
-    "@blocksuite/affine-widget-scroll-anchoring": "workspace:*",
     "@blocksuite/affine-widget-slash-menu": "workspace:*",
     "@blocksuite/affine-widget-toolbar": "workspace:*",
     "@blocksuite/data-view": "workspace:*",