feat: event message_ciphertext (#2292)

* add option cipherMsg

* add event  message_ciphertext

* example

* remove option cipherMsg

* removing unlinked code

* Update Client.js

---------

Co-authored-by: Shir Serlui <70711723+shirser121@users.noreply.github.com>
Co-authored-by: alechkos <93551621+alechkos@users.noreply.github.com>

example.js

@@ -386,6 +386,14 @@ client.on('message_create', (msg) => {
     }
 });
 
+client.on('message_ciphertext', (msg) => {
+    // Receiving new incoming messages that have been encrypted
+    // msg.type === 'ciphertext'
+    msg.body = 'Waiting for this message. Check your phone.';
+    
+    // do stuff here
+});
+
 client.on('message_revoke_everyone', async (after, before) => {
     // Fired whenever a message is deleted by anyone (including you)
     console.log(after); // message after it was deleted.