In the Win32 platform our setTitle() can properly assign a Unicode
utf-8 window title. Unfortunately our getTitle() will only read regular
8-bit character strings. This means that we can never compare what we
set to what we get. This patch updates getTitle() to use Unicode-aware
GetWindowTextLengthW and GetWindowTextW.
see T88909 for an example of this affecting user experience.
Differential Revision: https://developer.blender.org/D11782
Reviewed by Ray Molenkamp
b39d66adde