Support complex requests?

[tferr]

@gab1one , @ctrueden:

Before looking into #5 , I tried to replace all of our okhttp usage with scijava-io-http (which to be honest, I did not know it existed - sorry about that). Doing so would be nice as I would like to keep external dependencies to a minimum.

I can replace it fine for passive downloads, but I was unable to do so for instance with this json query (we also have other queries that are more complex here). Are such queries possible or even intended?