refactor ArtworkView so that draggable image can be changed from ViewController
change draggable image from View Controller
change mainPhoto type and add dimensions getter
add author field, set artworkView properties
add artworkView properties and set draggable properties on load
add artworkView properties and set draggable properties on load
create properties for title, author and dimensions; setting view on init
create details button outlet; connect it with tapping event
create artwork view height constant