* First cut image update for kubernetes support.
With this,
1) dockers dhcp_relay, lldp, pmon, radv, snmp, telemetry are enabled
for kube management
init_cfg.json configure set_owner as kube for these
2) Each docker's start.sh updated to call container_startup.py to register going up
As part of this call, it registers the current owner as local/kube and its version
The images are built with its version ingrained into image during build
3) Update all docker's bash script to call 'container start/stop/wait' instead of 'docker start/stop/wait'.
For all locally managed containers, it calls docker commands, hence no change for locally managed.
4) Introduced a new ctrmgrd service, that helps with transition between owners as kube & local and carry over any labels update from STATE-DB to API server
5) hostcfgd updated to handle owner change
6) Reboot scripts are updatd to tag kube running images as local, so upon reboot they run the same image.
7) Added kube_commands.py to handle all updates with Kubernetes API serrver -- dedicated for k8s interaction only.
As part of the transition from Python 2 to Python 3, we are installing both pip2 and pip3 in the slave and config-engine containers. This PR replaces calls to `pip` in these containers with an explicit call to `pip2` to ensure the proper version of pip is executed, no matter which version of pip is aliased to `pip`, as we no longer rely on that alias.
Also some other pip-related cleanup
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.