Consolidate common SONiC Python-language functionality into one shared package (sonic-py-common) and eliminate duplicate code.
The package currently includes three modules:
- daemon_base
- device_info
- logger
The `-sv2` suffix was used to differentiate SNMP Dockers when we transitioned from "SONiCv1" to "SONiCv2", about four years ago. The old Docker materials were removed long ago; there is no need to keep this suffix. Removing it aligns the name with all the other Dockers.
Also edit Monit configuration to detect proper snmp-subagent command line in Buster, and make snmpd command line matching more robust.