Implement dash:ImageViewer

[luizbonino]

As a metadata editor,
I want that the dash:ImageViewer to be implemented
So that the FDP displays the images present in the metadata schema,.

Acceptance Criteria:

• Criteria 1: the FDP's form generator displays the images referred by the URIs in the metadata schema that have been tagged with dash:ImageViewer.
• Criteria 2: The image is rendered in maximum height and width to avoid disruption of the rest of the rendered page.
• Criteria 3: The image can be clicked and the full-size image is loaded in a separate window.

Definition of Done:

• All acceptance criteria are met.
• Code is reviewed and approved.
• Necessary tests are written and pass.
• Documentation is updated, if applicable.
• Feature is deployed to the [environment name].