dev/core#679 fix loss of search results when including tags or groups.

dev/core#679 fix loss of search results when including tags or groups.

The bug as described was a bit tricksy to replicate as it is inconsistent and the
code is not actually outputting the tags/ groups. I think these are pre-existing issues

I was able to replicate by having 2 search profiles - one with only tags & one one with only groups & switching back & and force on output -  once I replicated I found that there was a regression due to

https://github.com/eileenmcnaughton/civicrm-core/commit/2ca46d4d5a8cd15929ac0939ca2bb380a3de027e#diff-e54381bfdf51e31cab376c71ca0d66ffR4967

whereby the groupBy had been dropped, causing the results to be squashed into a single row