Add link to metadata sheet in GN when a dataset is visualized

[ptaconet]

When a dataset is selected for visualization, add somewhere the link to redirect to the metadata sheet in Geonetwork, with a label such as " To get more information on this dataset, click here "

[eblondel]

I will possibly handle a metadata viewer in a dialog within the application instead, depending if I found the appropriate library to do so.

[ptaconet]

Great. If no appropriate library exists, such link could also be on the "browse" panel, with an icon on each dataset (in addition to the one that is already available for "add to basket" ).