make es_query raise an exception if there is an error

moving this pretty core functionality into es_query from es_wrapper

I did a good faith check at usages of es_query and none of them
check for an error field; so this just makes the exception that is raised
much more useful

Instead of KeyError 'hits', it'll give you the actual es error
catch another exception in callcenter post-sync edge case
Merge pull request #3610 from dimagi/es-exception

make es_query raise an exception if there is an error