feat: extending lock to single conversation to meta inbox (#9104)

This change introduces the ability to lock conversations to a single thread for Instagram and facebook messages within the Meta inbox, mirroring existing functionality in WhatsApp and SMS inboxes.

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

app/javascript/dashboard/routes/dashboard/settings/inbox/Settings.vue

@@ -589,7 +589,9 @@ export default {
       return this.inbox.name;
     },
     canLocktoSingleConversation() {
-      return this.isASmsInbox || this.isAWhatsAppChannel;
+      return (
+        this.isASmsInbox || this.isAWhatsAppChannel || this.isAFacebookInbox
+      );
     },
     inboxNameLabel() {
       if (this.isAWebWidgetInbox) {