feature: IRCv3 Multiline support

[poVoq]

✨ Describe the feature you'd like

Now that IRCv3 Multiline is starting to land in larger IRC networks like Libera.chat, it would be really nice if that was supported.

It would be definitely a huge improvement for our use of this library in the new community maintained fork of Matterbridge.

I think this was already mentioned and discussed in #42 but not yet implemented in #43

Thanks for looking into this!

🌧 Is your feature request related to a problem?

No response

🔎 Describe alternatives you've considered

No real alternatives.

⚠ If implemented, do you think this feature will be a breaking change to users?

No

⚙ Additional context

No response

🤝 Requirements

• I have confirmed that someone else has not submitted a similar feature request.
• If implemented, I believe this feature will help others, in addition to solving my problems.
• I have looked into alternative solutions to the best of my ability.
• (optional) I would be willing to contribute to testing this feature if implemented, or making a PR to implement this functionality.