Allow displayMessageForm to open itemId in same window
Currently displayMessageForm method is opening the message pointed by itemId in a new window.
It will be great if we could pass an option to the method Office.context.mailbox.displayMessageForm() that allows to replace the current visualized message with the new message indicated in itemId.
The use case that I want to enable here is to programmatically navigate with add-in javascript to arbitrary messages knowing their itemIds.
