CLOUDSTACK-6327: Updated the removeFromLoadBalancerRule and listLoadBalancerRuleInstances API

Updated these APIs to use VM primary/secondary details on LB rule.

listLoadBalancerRuleInstances API lists the vm ips which are assigned to lb rule when passed
listlbvmips
removeFromLoadBalancerRule is updated to remove the spcific vm ip entry assinged to LB rule.
Added new param vmidipmap to this API