feat: add support for sendTyping conv method

Author: korhaliv

package-lock.json

@@ -31,6 +31,14 @@ class UserConversation extends BaseConversation {
     return Number(timestamp);
   }
 
+  /**
+   * Send typing message to trigger a typing indicator for the recipient. Indicator will be shown for 15seconds unless a typing STOP message is sent first.
+   * @param {boolean} [stop] - if true stops typing
+   */
+  async sendTyping(stop = false) {
+    await this.client._busInterface.sendTyping(this.id, stop);
+  }
+
   /**
    * Reset the session keys for the conversation.
    * This method should rarely need to be used.