Tutorials browser now always appears on the mainframe. This avoids the browser appearing on small torn-off windows if content is torn off while a tutorial is in progress.
Also fixed crash when opening a browser from a widget that used to be docked to anotehr tab (weak window pointer was invalid at this point).
TTP# 347014 - EDITOR: TUTORIAL: If a tab is undocked while being referenced in the "welcome to the unreal editor" tutorial, there will be two instances of the tutorial text
[CL 2305366 by Thomas Sarkanen in Main branch]