[occm] remove SGs from non-existent nodes ports on Update

[EmilienM]

What this PR does / why we need it:

Update applyNodeSecurityGroupIDForLB() to also lookup ports that have the SG tag and detach the SG from the ports that don't belong to the ports of the current list of Nodes.

This will ensure ports are cleaned up if a Node is being removed from a Loadbalancer.

Which issue this PR fixes(if applicable): fixes #2695

Release note:

When a Node is removed from a load balancer, we'll now ensure that its ports don't have the security group associated
with the load balancer.