This merge request implements the third name format ("[NameDisplay](https://learn.microsoft.com/en-us/windows/win32/api/secext/ne-secext-extende...)") of the GetUserNameExW method.
-- v3: secur32: GetUserNameExW(3) is supposed to return ERROR_MORE_DATA if the buffer is too small, not ERROR_INSUFFICIENT_BUFFER secur32/tests: Add GetUserNameExW(3) specific test cases