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.
The `By` cannot be a title. It has to be part of the name as per the designs. This will mean duplicating some of that template here.

It should also be changed to `Added by`