feat(v4): Update the campaigns page design (#10371)

<img width="1439" alt="Screenshot 2024-10-30 at 8 58 12 PM"
src="https://github.com/user-attachments/assets/26231270-5e73-40fb-9efa-c661585ebe7c">


Fixes
https://linear.app/chatwoot/project/campaign-redesign-f82bede26ca7/overview

---------

Co-authored-by: Pranav <pranavrajs@gmail.com>
Co-authored-by: Shivam Mishra <scm.mymail@gmail.com>

app/javascript/dashboard/components-next/thumbnail/Thumbnail.vue

@@ -77,7 +77,7 @@ const onImgLoad = () => {
     class="flex items-center justify-center rounded-full bg-n-slate-3 dark:bg-n-slate-4"
     :style="{ width: `${size}px`, height: `${size}px` }"
   >
-    <div v-if="author">
+    <div v-if="author" class="flex items-center justify-center">
       <img
         v-if="shouldShowImage"
         :src="src"