add an "eventMapper" prop to calendar-google
add an "eventMapper" prop to calendar-google

allows editing events after they're fetched, but before they're rendered
in the list. Lets us take advantage of the new "config" property to
clean up events from certain data sources, if needed.

carls-app/carls,carls-app/carls,StoDevX/AAO-React-Native,StoDevX/AAO-React-Native,StoDevX/AAO-React-Native,StoDevX/AAO-React-Native,carls-app/carls,carls-app/carls,StoDevX/AAO-React-Native,carls-app/carls,StoDevX/AAO-React-Native,StoDevX/AAO-React-Native,carls-app/carls,carls-app/carls,StoDevX/AAO-React-Native,StoDevX/AAO-React-Native