Implement group chats in Moxxy

Group chats are an integral component of instant messaging clients used in everyday communication. However, Moxxy, currently lacks support for group chats. Hence, the objective of this project is to incorporate basic group chat functionality into Moxxy by integrating MUC support (XEP-0045) into the underlying Moxxmpp library. The proposed solution aims to be highly extensible, allowing for easy integration of future feature additions. The deliverables of this project include the addition of XEP-0045 support to Moxxmpp, along with basic MUC features such as joining and leaving rooms, sending messages, and changing nicknames, among others. By implementing these features, users of Moxxy will be able to enjoy group chat functionality, which is essential for effective communication.