MINOR: Use SS_Map::keys() and SS_Map::values() instead of array_keys() / array_values()
MINOR: Use SS_Map::keys() and SS_Map::values() instead of array_keys() / array_values()

dhensby/silverstripe-cms,jonom/silverstripe-cms,dhensby/silverstripe-cms,silverstripe-labs/silverstripe-reports,dhensby/silverstripe-cms,helpfulrobot/i-lateral-silverstripe-siteconfig,silverstripe/silverstripe-cms,silverstripe/silverstripe-cms,jonom/silverstripe-cms,dhensby/silverstripe-reports,dhensby/silverstripe-reports,silverstripe-labs/silverstripe-reports,silverstripe/silverstripe-siteconfig