Enhancement/View document metadata #200
In #174, @prokotg suggested to enable the user to view document metadata while annotating. This is a very useful feature for large scale annotation projects on diverse datasets in order to enable the annotator to have more context on the document, e.g. providing links to related documents, providing a link to a source PDF document or image from which text was extracted, etc.
As such, this change implements a simple extension to the annotator page which adds a button to view the document metadata. The new button follows the existing example of the annotation guideline button and displays the metadata in a modal. If there is no metadata, the button is disabled.
The animation below shows the new metadata display button in action: