Add support for binary widget in non binary fields
A chart field and XML view with the binary widget, the icon to download doesn't work
For example, can't download the Sepa Message [1]
[1] https://bitbucket.org/tryton/account_payment_sepa/src/59279c1737a37ea7874a6c6a63c07b9d902dd9a3/view/message_form.xml?at=default&fileviewer=file-view-default#message_form.xml-12