EZP-23728: As an editor, I want to see the content of the binaryfile fields

JIRA: https://jira.ez.no/browse/EZP-23728

# Description

This patch adds the field view for the BinaryFile fields.

![binaryfile](https://cloud.githubusercontent.com/assets/305563/5294720/10ec989c-7b8a-11e4-9a84-178bf22f6d3a.png)

## Known issues / limitations

* The size is always in bytes as this is also connected to [the localization issue](https://jira.ez.no/browse/EZP-23429) that will be fixed later
* The link to download the file points to the actual file instead of *content/download* as [this feature is missing](https://jira.ez.no/browse/EZP-23550) in the Symfony stack and no info is provided on the correct URL by the REST API.

# Tests

unit tests + manual test