Support for JSON output, similar to new Twitch EventSub format

[RAnders00]

Twitch has added support for receiving chat message events over EventSub:
https://dev.twitch.tv/docs/eventsub/eventsub-subscription-types/#channelchatmessage
https://dev.twitch.tv/docs/eventsub/eventsub-reference/#channel-chat-message-event

recent-messages2 could support output messages in this format instead of raw IRC. An additional new optional query parameter would have to be added to switch to this json output method.

[RAnders00]

This might be a feature to add to twitch-irc-rs, but I haven't decided on that yet. The most through approach might be to add support for EventSub to twitch-irc-rs or to make a new crate that contains support for connecting to Twitch chat over EventSub, and then to use the types from that crate.