Search organization names as well as person names

Refactor out the name_search method to utils and use that for searching
organizations too. Then use it to search both the organizations and
persons and concatenate the results.

Add a label to the results to indicate what type of entity each result
is just in case.

Fixes #476 

NB: this doesn't use elasticsearch from the API as looking at it the code to do that is going to be reasonably grim and probably a bit fragile.