Query factory always return result

This will reduce the number of potential errors resulting from failing queries and database connection issues (by always ensuring a queryFactoryResult object is returned). In the past either a boolean (true and false), null, or a queryFactoryResult would be returned by query_factory when Execute or ExecuteRandomMulti was called. This change should help simplify working with the database in Zen Cart when utilizing query_factory.

This allows code to simply check "$result->EOF" or "$result->RecordCount()" instead of needing to check if $result is true, false, null, or a queryFactoryResult object. In the event an error or no data is returned "$result->EOF" will return true and "$result->RecordCount()" will return 0.

<sub>***NOTE:*** Most of the existing Zen Cart code and 3rd Party "plugins" typically check either "$result->EOF" or "$result->RecordCount()".</sub>