cursors of any size on win32

[Antoine Martin]

Split from #976, related to #734.

See ticket:976#comment:12.

Links claiming we can only have fixed size (32x32 or 64x64 on high dpi displays):

• ​About Cursors
• ​CreateCursor: The nWidth and nHeight parameters must specify a width and height that are supported by the current display driver, because the system cannot create cursors of other sizes. To determine the width and height supported by the display driver, use the GetSystemMetrics? function, specifying the SM_CXCURSOR or SM_CYCURSOR value.
• ​The biggest size of Windows Cursor
• ​GetSystemMetrics function:
  • SM_CXCURSOR: The width of a cursor, in pixels. The system cannot create cursors of other sizes.
  • SM_CYCURSOR: The height of a cursor, in pixels. The system cannot create cursors of other sizes.

That said, I also found: ​Windows XP icon and cursor support which states: The system also provides the SetSystemCursor? API function that you can use to change the system cursor for specific categories. You can use this function to set a cursor of any size. However, you must call the function programmatically, and you can only use it to set a cursor for a specific category. You cannot use it to make all cursors on the system the same size.