[CODE] Enable drag and drop on Shortcuts View and add 'properties' in its context menu

I couldn't find a way to create a pull request. This code (for thunar 4.16.10) is working and these 2 features are a must that I have been missing since forever.

The only thing missing is when the user inserts a portable storage unit (e.g. USB stick). In this case we need to update file pointer -- maybe in thunar_shortcuts_view_open() inside if (G_LIKELY (THUNAR_IS_DEVICE (device))) scope?