Improve contents counter for dataverses

[bryanmgee]

Currently, the way the script works, it only detects immediately nested objects within a target dataverse. Given this hypothetical structure, for example:

--nested dataverse 1
----dataset A
----dataset B
--nested dataverse 2
----dataset C
--dataset D

The script will return 2 dataverses and 1 dataset because it did not look into the two dataverses (requires a separate API call for each). There are probably two ways to do this. One is to retrieve the names of any nested dataverses, explode the df (one nested dataverse per row), and use a look-up function to add further nested items until we get to a level where there are no more nested dataverses. The other is to iterate through this in the API call and get the script to keep pinging the API until it doesn't find any 'dataverse' objects.