feat(editor): improve visibility of hidden content of edgeless note (#12068)

Close [BS-3066](https://linear.app/affine-design/issue/BS-3066/优化长note的展示和折叠)

- Enhanced the visibility behavior of hidden content in edgeless notes by:
  - Showing hidden content when a note is being edited, even when it's outside the viewport
  - Improving hover behavior with a delay when leaving from the bottom of the note
  - Adding proper cleanup of hover timeouts when the component is disconnected
  - Optimizing the viewport element to keep editing blocks or elements visible

## Testing
- Added new E2E test cases covering:
  - Hover behavior on selected notes
  - Content visibility during editing
  - Viewport scrolling behavior
  - Edge cases for content visibility

## Impact
This change improves the user experience when working with collapsed notes in edgeless mode by making the content more accessible and preventing accidental content hiding during editing.

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

- **Bug Fixes**
	- Improved visibility of hidden content in edgeless notes when hovering near the bottom edge or editing the note, especially after resizing or clipping.
- **New Features**
	- Enhanced hover behavior with delayed clearing based on mouse position to improve user experience.
- **Tests**
	- Added new tests verifying hidden content visibility in edgeless notes during hover and editing, simulating diverse user interactions.
- **Chores**
	- Added utilities to get and set viewport center for improved test control.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

tests/blocksuite/e2e/utils/actions/edgeless.ts

@@ -970,6 +970,25 @@ export async function getZoomLevel(page: Page) {
   return Number(text.replace('%', ''));
 }
 
+export async function getViewportCenter(page: Page): Promise<[number, number]> {
+  return page.evaluate(() => {
+    const target = document.querySelector('affine-edgeless-root');
+    if (!target) {
+      throw new Error('Missing edgeless page');
+    }
+    return [target.gfx.viewport.centerX, target.gfx.viewport.centerY];
+  });
+}
+export async function setViewportCenter(page: Page, center: [number, number]) {
+  await page.evaluate(center => {
+    const target = document.querySelector('affine-edgeless-root');
+    if (!target) {
+      throw new Error('Missing edgeless page');
+    }
+    target.gfx.viewport.setCenter(center[0], center[1]);
+  }, center);
+}
+
 export async function optionMouseDrag(
   page: Page,
   start: number[],