NMS-6746: Improve readability SnmpMonitor

- Table for Operation mode reformatted in source
- Description table shortened
- Operator description added force line breaks
- Changed snmp-config.xml format as file
- Reformatted examples and the used OIDs
- Renamed the example service from All_Static_Routes to All-Static-Routes to look less like source code
---We use as an scalar object id the physical drive status given by the following tabular OID:
+++We use as a scalar object id the physical drive status given by the following tabular OID: