geocode: Return value should depend on `output` even if errors occur

If I query a geocode using the output = "more" option, and some error occurs (e.g. OVER_QUERY LIMIT) the result will be a data.frame with only two columns ("lat" and "lon"). Those two are NA.

It should be a data frame with 13 columns, all of which NA.

Start by locating the geocode entry point and the handling for output="more" when an error such as OVER_QUERY LIMIT occurs. Reproduce the error and inspect the returned data frame; done means the error result has 13 columns, with every value set to NA.

Written by the indexing model from the issue text.