Add a gallery view to Explore Data page

[codytodonnell]

Implement a feature similar to the gallery view in the GBIF occurrence search page. There should be a new toggle button above the table that hides the <DataGrid> and shows a gallery of the data items instead.

The first pass of this feature could just show, for each data item, a box with two or three fields in it (like scientific name, date, and region). If possible, you could try to display an image for the data item if it exists, using the media field from GBIF.