Add file count info in audit log to record the file count for delete and getListing RPC request to assist user trouble shooting when RPC cost is increasing

Currently, there is no file count in audit log for delete and getListing RPC request, therefore， for the increasing RPC call, it is not easy to configure it out whether the time-consuming RPC  request is related to too many files be operated in the RPC request.

Therefore, It it necessary to add file count info in the audit log to assist maintenance