Win32 specific: Using SHChangeNotifyRegister to get notifications

on removable media insert / eject events.
From now on we no more poll for removable media on Windows.

Thanks @mjgtp from prusaprinters.org
See the following discussion:
https://forum.prusaprinters.org/forum/prusaslicer/prusaslicer-trying-to-access-my-floppy-disk-a

The final working code sample was taken from Chromium source code,
volume_mount_watcher_win.cc

src/slic3r/GUI/MainFrame.hpp

@@ -144,6 +144,8 @@ public:
 
 #ifdef _WIN32
     void*				m_hDeviceNotify { nullptr };
+    uint32_t  			m_ulSHChangeNotifyRegister { 0 };
+	static constexpr int WM_USER_MEDIACHANGED { 0x7FFF }; // WM_USER from 0x0400 to 0x7FFF, picking the last one to not interfere with wxWidgets allocation
 #endif // _WIN32
 };