Fix import importing twice

[birdddev]

Also removes the <TargetBox> from the Import dock.
TargetBox is completely un-used now.

[rvion]

Can we still import import workflows or images by drag and dropping anything anywhere in the app ? I thought it would be cool if we had a global drop handler on the whole app itself

[birdddev]

You already have it going to the document.body as well useGlobalDropHook, which is the one that actually handles all of the file types, TargetBox only did images, not urls it looked like.
It was good you mentioned you set up the url dragging, because I initially commented out useGlobalDropHook first and then tested it and it only worked for files.

[birdddev]

This broke dragging images from inside cushy though.
May just have to move the useGlobal stuff to TargetBox, I'll look in to it later 😔