fix: Avoid overflowing submenus in conversation context menu (#5113)

* Scroll overflowing content inside submenus

* Disable submenus if options are not available

app/javascript/dashboard/components/widgets/conversation/contextMenu/Index.vue

@@ -17,7 +17,10 @@
         @click="snoozeConversation(option.snoozedUntil)"
       />
     </menu-item-with-submenu>
-    <menu-item-with-submenu :option="labelMenuConfig">
+    <menu-item-with-submenu
+      :option="labelMenuConfig"
+      :sub-menu-available="!!labels.length"
+    >
       <template>
         <menu-item
           v-for="label in labels"
@@ -28,7 +31,10 @@
         />
       </template>
     </menu-item-with-submenu>
-    <menu-item-with-submenu :option="agentMenuConfig">
+    <menu-item-with-submenu
+      :option="agentMenuConfig"
+      :sub-menu-available="!!assignableAgents.length"
+    >
       <agent-loading-placeholder v-if="assignableAgentsUiFlags.isFetching" />
       <template v-else>
         <menu-item
@@ -40,7 +46,10 @@
         />
       </template>
     </menu-item-with-submenu>
-    <menu-item-with-submenu :option="teamMenuConfig">
+    <menu-item-with-submenu
+      :option="teamMenuConfig"
+      :sub-menu-available="!!teams.length"
+    >
       <menu-item
         v-for="team in teams"
         :key="team.id"