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/nodeSearchBox.spec.ts

@@ -79,6 +79,7 @@ test.describe('Node search box', { tag: '@node' }, () => {
     'Can auto link batch moved node',
     { tag: '@screenshot' },
     async ({ comfyPage }) => {
+      await comfyPage.settings.setSetting('Comfy.Graph.AutoPanSpeed', 0)
       await comfyPage.workflow.loadWorkflow('links/batch_move_links')
 
       // Get the CLIP output slot (index 1) from the first CheckpointLoaderSimple node (id: 4)