Arvados » Arvados Workbench 2

As a user I would like to be able to see data explorer item's details
so I can easily check when item was created, modified, what owner of the item is etc

Acceptance criteria:
- icon to open/hide details panel (see mockups)
- open/close animation
- panel close button
- item title and icon
- two tabs inside (details / activity)
- common resource information in details tab (see common resources field in http://doc.arvados.org/api/resources.html),
for this task no real data is needed - put placeholders

User flow:

1a. Click on " i " icon to open right side panel and then select item from content list.
1b. Select item from content list and then click on " i " icon to open right side panel.

2. See the details of selected item.