refactor: rewrite blocksuite dnd (#9595)

### Changed

- Refactored BlockSuite drag-and-drop using @atlaskit/pragmatic-drag-and-drop/element/adapter.
- Updated block dragging to use the new drag-and-drop infrastructure.

### BlockSuite DND API

Access the BlockSuite drag-and-drop API via `std.dnd`. This is a lightweight wrapper around pragmatic-drag-and-drop, offering convenient generic types and more intuitive option names.

#### Drag payload structure
There's some constrain about drag payload. The whole drag payload looks like this:

```typescript
type DragPayload = {
  entity: {
    type: string
  },
  from: {
    at: 'blocksuite',
    docId: string
  }
}
```
- The `from` field is auto-generated—no need for manual handling.
- The `entity` field is customizable, but it must include a `type`.

All drag-and-drop methods accept a generic type for entity, ensuring more accurate payloads in event handlers.

```typescript
type BlockEntity = {
  type: 'blocks',
  blockIds: string[]
}

dnd.draggable<BlockEntity>({
  element: someElement,
  setDragData: () => {
    // the return type must satisfy the generic type
    // in this case, it's BlockEntity
    return {
      type: 'blocks',
      blockIds: []
    }
  }
});

dnd.monitor<BlockEntity>({
  // the arguments is same for other event handler
  onDrag({ source }) {
    // the type of this is BlockEntity
    source.data.entity
  }
})
```

#### Drop payload
When hover on droppable target. You can set drop payload as well. All drag-and-drop methods accept a second generic type for drop payload.

The drop payload is customizable. Additionally, the DND system will add an `edge` field to the final payload object, indicating the nearest edge of the drop target relative to the current drag position.

```typescript
type DropPayload = {
  blockId: string;
}

dnd.dropTarget<BlockEntity, DropPayload>({
  getData() {
    // the type should be DropPayload
    return {
      blockId: 'someId'
    }
  }
});

dnd.monitor<BlockEntity, DropPayload>({
  // drag over on drop target
  onDrag({ location }) {
    const target = location.current.dropTargets[0];

    // the type is DropPayload
    target.data;
    // retrieve the nearest edge of the drop target relative to the current drop position.
    target.data.edge;
  }
})
```

blocksuite/affine/components/src/drag-indicator/file-drop-manager.ts

@@ -58,6 +58,8 @@ export class FileDropExtension extends LifeCycleWatcher {
 
   point$ = signal<Point | null>(null);
 
+  private _disableIndicator = false;
+
   closestElement$ = signal<BlockComponent | null>(null);
 
   dropTarget$ = computed<DropTarget | null>(() => {
@@ -196,7 +198,9 @@ export class FileDropExtension extends LifeCycleWatcher {
 
     std.event.disposables.add(
       this.dropTarget$.subscribe(target => {
-        FileDropExtension.indicator.rect = target?.rect ?? null;
+        FileDropExtension.indicator.rect = this._disableIndicator
+          ? null
+          : (target?.rect ?? null);
       })
     );
 
@@ -210,6 +214,17 @@ export class FileDropExtension extends LifeCycleWatcher {
         this.dragging$.value = false;
       })
     );
+    std.event.disposables.add(
+      std.dnd.monitor({
+        onDragStart: () => {
+          this._disableIndicator = true;
+        },
+        onDrop: () => {
+          this._disableIndicator = false;
+        },
+      })
+    );
+
     std.event.disposables.add(
       std.event.add('nativeDragOver', context => {
         const event = context.get('dndState').raw;