Geo context suggester: Require precision in mapping

The default precision was way too exact and could lead people to
think that geo context suggestions are not working. This patch now
requires you to set the precision in the mapping, as elasticsearch itself
can never tell exactly, what the required precision for the users
suggestions are.

Closes #5621
Made template endpoint compatible with search endpoint

Before this the from/size parameters did not work.
Also updated the rest api spec definition file with all the query_string
parameters.

Fixes #5550
[DOCS] remove extraneous ` from cache page