LPS-46622 See docs metadata from workflow task

It is needed because, when a reviewer is validating a document, he/she needs to
be able to see its medata and the download button.

This problem happens from My workflow tasks and My workflowInstances

Before:
![before](https://cloud.githubusercontent.com/assets/2162403/2902860/c52ec7bc-d5ea-11e3-9df1-a598e1581bd3.png)

After:
![after](https://cloud.githubusercontent.com/assets/2162403/2902859/c52b76a2-d5ea-11e3-821f-b1c4cda39945.png)