This is mostly just for text type messages at the moment but give the framework so that when other message types can be sent in threads they can be added easily
Create Message attached property to propagate parameters like room, timeline, index and maxContentWidth down to the message content avoiding lots of boilerplate
It isn't the right kind of interaction on a computer with a mouse or
trackpad, it should be relegated to touchscreen only. This should
hopefully cover everything from room list delegates to messages.