Add the missing operational tools for the WMAT0

Add the two missing SLS alarms:

- Simplified version of the paused jobs alarm, since WMStats provide most of the information
- Rewritten long jobs alarm that is independent of the batch system and more descriptive

Also refactor the directories to follow usual conventions in bin (no .py extension) and remove
the operations directory to make sure that the SLSAlarmsConfig is shipped in the rpm.
Merge pull request #4037 from dballesteros7/operational-tools

Add the missing operational tools for the WMAT0