Phased Interactive Message Support

The team has documented the Slack and Telegram approach to supporting interactive messages in bots here. The Slack approach requires the construct of an App, which is being implemented by Rocket.chat. But integrating with this app construct (via a manifest file) is a more difficult challenge and requires integration/coordination with others in the Rocket.chat team.

So for phase one, we are implementing essentially the Telegram approach, which sets RequestURL at configuration time and does not require the notion of an app to support full interactive messages.

Eventually, Rocket.chat will support both approaches.