MDL-47900 tool_monitor: created list of rules MUC
MDL-47900 tool_monitor: prevent unnecessary event insertions

With the introduction of the MUC we now check to see if a rule
exists for a particular event before we insert it.
MDL-47900 tool_monitor: fixed unit tests so they pass

Also expanded on the unit tests to confirm that the unnecessary
events are not being stored in the DB.