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/Campaigns/CampaignLayout.vue

@@ -0,0 +1,52 @@
+<script setup>
+import Button from 'dashboard/components-next/button/Button.vue';
+
+defineProps({
+  headerTitle: {
+    type: String,
+    default: '',
+  },
+  buttonLabel: {
+    type: String,
+    default: '',
+  },
+});
+
+const emit = defineEmits(['click', 'close']);
+
+const handleButtonClick = () => {
+  emit('click');
+};
+</script>
+
+<template>
+  <section class="flex flex-col w-full h-full overflow-hidden bg-n-background">
+    <header class="sticky top-0 z-10 px-6 lg:px-0">
+      <div class="w-full max-w-[900px] mx-auto">
+        <div class="flex items-center justify-between w-full h-20 gap-2">
+          <span class="text-xl font-medium text-n-slate-12">
+            {{ headerTitle }}
+          </span>
+          <div
+            v-on-clickaway="() => emit('close')"
+            class="relative group/campaign-button"
+          >
+            <Button
+              :label="buttonLabel"
+              icon="i-lucide-plus"
+              size="sm"
+              class="group-hover/campaign-button:brightness-110"
+              @click="handleButtonClick"
+            />
+            <slot name="action" />
+          </div>
+        </div>
+      </div>
+    </header>
+    <main class="flex-1 px-6 overflow-y-auto lg:px-0">
+      <div class="w-full max-w-[900px] mx-auto py-4">
+        <slot name="default" />
+      </div>
+    </main>
+  </section>
+</template>