Batch Drag & Drop Images (#8282)

## Summary

<!-- One sentence describing what changed and why. -->
Added feature to drag and drop multiple images into the UI and connect
them with a Batch Images node with tests to add convenience for users.
Only works with a group of images, mixing files not supported.

## Review Focus
<!-- Critical design decisions or edge cases that need attention -->
I've updated our usage of Litegraph.createNode, honestly, that method is
pretty bad, onNodeCreated option method doesn't even return the node
created. I think I will probably go check out their repo to do a PR over
there. Anyways, I made a createNode method to avoid race conditions when
creating nodes for the paste actions. Will allow us to better
programmatically create nodes that do not have workflows that also need
to be connected to other nodes.

<!-- If this PR fixes an issue, uncomment and update the line below -->

https://www.notion.so/comfy-org/Implement-Multi-image-drag-and-drop-to-canvas-2eb6d73d36508195ad8addfc4367db10

## Screenshots (if applicable)

https://github.com/user-attachments/assets/d4155807-56e2-4e39-8ab1-16eda90f6a53

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8282-Batch-Drag-Drop-Images-2f16d73d365081c1ab31ce9da47a7be5)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Alexander Brown <drjkl@comfy.org>
Co-authored-by: Austin Mroz <austin@comfy.org>

src/utils/litegraphUtil.ts

@@ -1,9 +1,14 @@
 import _ from 'es-toolkit/compat'
 
-import type { ColorOption, LGraph } from '@/lib/litegraph/src/litegraph'
+import type {
+  ColorOption,
+  LGraph,
+  LGraphCanvas
+} from '@/lib/litegraph/src/litegraph'
 import {
   LGraphGroup,
   LGraphNode,
+  LiteGraph,
   Reroute,
   isColorable
 } from '@/lib/litegraph/src/litegraph'
@@ -18,6 +23,8 @@ import type {
   WidgetCallbackOptions
 } from '@/lib/litegraph/src/types/widgets'
 import type { InputSpec } from '@/schemas/nodeDef/nodeDefSchemaV2'
+import { useToastStore } from '@/platform/updates/common/toastStore'
+import { t } from '@/i18n'
 
 type ImageNode = LGraphNode & { imgs: HTMLImageElement[] | undefined }
 type VideoNode = LGraphNode & {
@@ -25,6 +32,38 @@ type VideoNode = LGraphNode & {
   imgs: HTMLVideoElement[] | undefined
 }
 
+/**
+ * Extract & Promisify Litegraph.createNode to allow for positioning
+ * @param canvas
+ * @param name
+ */
+export async function createNode(
+  canvas: LGraphCanvas,
+  name: string
+): Promise<LGraphNode | null> {
+  if (!name) {
+    return null
+  }
+
+  const {
+    graph,
+    graph_mouse: [posX, posY]
+  } = canvas
+  const newNode = LiteGraph.createNode(name)
+  await new Promise((r) => setTimeout(r, 0))
+
+  if (newNode && graph) {
+    newNode.pos = [posX, posY]
+    const addedNode = graph.add(newNode) ?? null
+
+    if (addedNode) graph.change()
+    return addedNode
+  } else {
+    useToastStore().addAlert(t('assetBrowser.failedToCreateNode'))
+    return null
+  }
+}
+
 export function isImageNode(node: LGraphNode | undefined): node is ImageNode {
   if (!node) return false
   return (