indicate "size" of a dataverse in card when browsing

[pameyer]

Passing on a usability / "what's in this thing" suggestion:

When browsing, the dataverse card (??) doesn't currently provide any indication about how many datasets or sub-dataverses are contained within that dataverse; which can end up with a user exploring empty dataverses. One way to address this might be to add two counters to the dataverse card, one for datasets and one for sub-dataverses.

[pdurbin]

@pameyer I'm reminded about how early mockups for Dataverse 4.0 showed "cards" for dataverses with lists of datasets and "view more", like this but I think we didn't end up implementing this for performance reasons: