logic.action.user_show is slow

[toby]

This is a very slow call it would benefit from the sort of speed-ups that package-search received

for me locally this is taking 6 seconds for rufus using the datahub data I have I think a lot of this is the dataset retrival/dictization can we just grab json blobs from solr?

also is it possible to specify a sort order/paging?

I've put this as a demo-theme ticket as it is an big issue on the demo we are at 25 second page loads - which i can get down to about 8.8 secs so this is the main pain point now