Minimum and Maximum size become incorrect when the HiDPI factor changes

On most platforms, the set_min_inner_size and set_max_inner_size functions don't handle HiDPI factor changes properly.

Most of the current implementations perform the coordinate-system conversion within the calls to set_{whatever}_size, and store the internal size bounds as either a PhysicalSize or a LogicalSize. That's almost the correct behavior, but it breaks when the window's HiDPI factor changes: if set_{whatever}_size had to do a coordinate system conversion from logical->physical or physical->logical, the size bound will no longer be accurate to what the user requested, since the coordinate system conversion will have changed. Winit should store the Size parameter when one of those functions is called, and update the value passed to the OS whenever a HiDPIFactorChanged event is received.

Start by locating the platform implementations of set_min_inner_size and set_max_inner_size, then trace how HiDPIFactorChanged events are handled. Verify that the requested Size remains accurate after the HiDPI factor changes and that the updated value passed to the OS matches the original request.