Add support for reply-parent tags

[Retoon]

I noticed there wasn't support for reply-parent tags, these tags contain information about a message a user is replying to in chat, the tags are optional and not present when the message is not in reply to another message.
see: https://dev.twitch.tv/docs/irc/tags/#twitch-irc-tags

I suggest something like a ReplyParent struct type that contains the five reply-parent related tags, msg-id, user-login, user-login, display-name, msg-body

if i have time i'll try to fork and implement it but i'm not terribly familiar with developing crates or libraries, but will give it a shot.

[Retoon]

I opened a pull request ( #189 ). This is my first time doing a (proper) pull request so there's a good chance i missed something that i needed to do.

[DanielHe4rt]

The project still being maintained?

[Retoon]

The project still being maintained?

I don't know why you're asking in this issue specifically, but i'm sure @RAnders00 is just busy.

[RAnders00]

Added via #189