This method will return a list of categories and location counts, given the input criteria.

Return Value: RestCatSum

Note that, since one location can be assigned to multiple categories, the counts will not add up to the total number of locations.

Country ID is required. For the US, city name cannot be specified without also specifying state.

For countries other than the US, state can only be used if state/province is stored in the designated field in our system, and not as part of a free-form international address.