Autopan canvas when dragging nodes/links to edges (#8773)

## Summary

Adds autopanning so the canvas moves when you drag a node/link to the
side of the canvas

## Changes

- **What**: 
- adds autopan controller that runs on animation frame timer to check
autopan speed
- extracts updateNodePositions for reuse
- specific handling for vue vs litegraph modes
- adds max speed setting, allowing user to set 0 for disabling

## Screenshots (if applicable)

https://github.com/user-attachments/assets/1290ae6d-b2f0-4d63-8955-39b933526874

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8773-Autopan-canvas-when-dragging-nodes-links-to-edges-3036d73d365081869a58ca5978f15f80)
by [Unito](https://www.unito.io)

---------

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

browser_tests/tests/rightClickMenu.spec.ts

@@ -123,6 +123,7 @@ test.describe('Node Right Click Menu', { tag: ['@screenshot', '@ui'] }, () => {
   })
 
   test('Can pin and unpin', async ({ comfyPage }) => {
+    await comfyPage.settings.setSetting('Comfy.Graph.AutoPanSpeed', 0)
     await comfyPage.canvas.click({
       position: DefaultGraphPositions.emptyLatentWidgetClick,
       button: 'right'