feat(editor): add page dragging area widget extension (#12045)

Closes: BS-3364

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

- **New Features**
  - Introduced a new "Page Dragging Area" widget, enabling enhanced block selection and drag area detection within the user interface.
  - Added utilities for more precise block selection based on rectangular selection areas.

- **Improvements**
  - Integrated the new widget into the view extension system for consistent behavior across supported views.
  - Enhanced clipboard handling with comprehensive adapter configurations for various data types.

- **Refactor**
  - Streamlined widget registration and block selection logic for improved maintainability and modularity.
  - Removed legacy widget exports and registrations to centralize widget management.

- **Chores**
  - Updated workspace and TypeScript configurations to support the new widget module.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/widgets/page-dragging-area/package.json

@@ -0,0 +1,42 @@
+{
+  "name": "@blocksuite/affine-widget-page-dragging-area",
+  "description": "Affine page dragging area widget.",
+  "type": "module",
+  "scripts": {
+    "build": "tsc"
+  },
+  "sideEffects": false,
+  "keywords": [],
+  "author": "toeverything",
+  "license": "MIT",
+  "dependencies": {
+    "@blocksuite/affine-components": "workspace:*",
+    "@blocksuite/affine-ext-loader": "workspace:*",
+    "@blocksuite/affine-model": "workspace:*",
+    "@blocksuite/affine-shared": "workspace:*",
+    "@blocksuite/global": "workspace:*",
+    "@blocksuite/icons": "^2.2.12",
+    "@blocksuite/std": "workspace:*",
+    "@blocksuite/store": "workspace:*",
+    "@lit/context": "^1.1.2",
+    "@preact/signals-core": "^1.8.0",
+    "@toeverything/theme": "^1.1.12",
+    "@types/lodash-es": "^4.17.12",
+    "fflate": "^0.8.2",
+    "lit": "^3.2.0",
+    "lodash-es": "^4.17.21",
+    "rxjs": "^7.8.1"
+  },
+  "exports": {
+    ".": "./src/index.ts",
+    "./effects": "./src/effects.ts",
+    "./view": "./src/view.ts"
+  },
+  "files": [
+    "src",
+    "dist",
+    "!src/__tests__",
+    "!dist/__tests__"
+  ],
+  "version": "0.21.0"
+}