new-chat-dialog: Show dummy contact if length is less than 3 and greater than 0

In the new chat dialog, the Dummy contact only shows up if the length is greater than 3 which is a bit confusing if one is inputting a new number.

This MR allows the dummy contact to show up if the length is less than 3.

There was also some spacing issues fixed in a different commit. Feel free to drop it if you don't want them (or you want to add them yourself to not mess up git blame).