Enhancement: Details in Sharing Sidebar

We're now displaying more information about the 
highlighted file in the sharing sidebar, including 
a preview (if applicable) as well as sharing and 
version information in one place.

https://github.com/owncloud/web/issues/5161
https://github.com/owncloud/web/pull/5284
https://github.com/owncloud/web/pull/5483
