Create the 'About content' widget

There should be an aboutcontent widget that has 2 different tabs. The first tab is the Details tab and shows the metadata of the content (title, description, url, created by). When a description is not available, it should not be shown. The second tab is the Shared with tab and shows the list of members of the content.
This was caused by a previous followup on review where I removed the max-height and overflow properties from the infinite scroll container. It needs it to do appropriate paging when scrolling. If it's not there infinite scroll won't work properly.