Add isRedeem and isHighlight fields to TwitchPrivateMessage

[crutchcorn]

Feature Request

I have an app that I would like to show both messages and redemptions on. However, I don't want to show the redeems (even those with messages) inline alongside the chat messages.

To help with that, it would be nice to have a msg.isRedeem field. Likewise, I want to treat a "highlighted message" (a built-in redeem that's got different identifying tags) as a redeem as well. As such, it'd be helpful to have a msg.isHighlighted field too

I have a PR that would be ready-to-go if this feature idea is approved

[d-fischer]

Seems fine to me, although I'd prefer the first one to be named isRedemption.

[crutchcorn]

Awesome, PR opened - thanks!