Add asset deletion progress indicator (#7906)

## Summary

Currently the delay between user action and visual response is too long
and it looks like it hasn't worked.
This adds a visual indicator that the action is processing.

## Changes

- add loading indicator while asset is deleting

## Screenshots (if applicable)
(Artifically delayed deletion)


https://github.com/user-attachments/assets/a9a8b9fe-896d-4666-b643-ec8b990f6444

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7906-Add-asset-deletion-progress-indicator-2e26d73d365081ed82b8e770ba3d0615)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Alexander Brown <drjkl@comfy.org>
Co-authored-by: Jin Yi <jin12cc@gmail.com>

src/components/common/LoadingOverlay.vue

@@ -0,0 +1,49 @@
+<template>
+  <Transition name="fade">
+    <div
+      v-if="loading"
+      class="absolute inset-0 z-50 flex items-center justify-center bg-backdrop/50"
+    >
+      <div class="flex flex-col items-center">
+        <div class="grid place-items-center">
+          <div
+            :class="
+              cn(
+                'col-start-1 row-start-1 animate-spin rounded-full border-muted-foreground border-t-base-foreground',
+                spinnerSizeClass
+              )
+            "
+          />
+          <div class="col-start-1 row-start-1">
+            <slot />
+          </div>
+        </div>
+        <div v-if="loadingMessage" class="mt-4 text-lg text-base-foreground">
+          {{ loadingMessage }}
+        </div>
+      </div>
+    </div>
+  </Transition>
+</template>
+
+<script setup lang="ts">
+import { computed } from 'vue'
+
+import { cn } from '@/utils/tailwindUtil'
+
+const { size = 'md' } = defineProps<{
+  loading: boolean
+  loadingMessage?: string
+  size?: 'sm' | 'md'
+}>()
+
+const spinnerSizeClass = computed(() => {
+  switch (size) {
+    case 'sm':
+      return 'h-6 w-6 border-2'
+    case 'md':
+    default:
+      return 'h-12 w-12 border-4'
+  }
+})
+</script>