remove activities_count from dataset api
remove activities_count from dataset api

zimmerman-zimmerman/OIPA,zimmerman-zimmerman/OIPA,zimmerman-zimmerman/OIPA,openaid-IATI/OIPA,zimmerman-zimmerman/OIPA,openaid-IATI/OIPA,openaid-IATI/OIPA,zimmerman-zimmerman/OIPA,openaid-IATI/OIPA,openaid-IATI/OIPA