Set costs and parallel settings on tiger functions

[robe]

Now that 9.6 is the minimum I can set costs and parallel settings.

I discovered one of my geocodings was slower in PostgreSQL 12 because the geocoding process was repeating for each because the CTE is not always materialized now. Setting costs high setting expected rows returned from default 1000 to 1 alleviates that.

In fact the ROWS count seemed to have a much greater impact than anything else.