Add a "/users"-like API method that supports display names. This will let bot commands which have a username parameter support Asian-family character display names to be passed the same as Roman-alphabet channel names. It will also let systems verify that a provided name (channel or display) exists on Twitch, and merge any information for a user's display name with the information for that user's channel name, to prevent "duplicate" sets of data: one for the display name; one for the channel name.