Improve cloudbackup_mon.sh

Changes:
* Report on all backup configs.
* If an optional backup config ID is given as an argument, just report on that backup.
* Add the backup config ID and name to the generated metrics.
* Use a unique temporary file name so the script can be run at the same time with different configs

Also:
* Replace `cat < file | grep`  with `grep < file`
* Replace `sed | sed` with 1 `sed`