Add conditional use balancer public ip and create role assignment on …

[gustavoborragan]

…AKS module

[alambike]

New block to configure the outbound public IPs in the balancer:

outbound_public_ips:
 - id: 
or
 - resource_group:
 - name:

For every outbound_public_ips,a Network Contributor role has to be assigned to the system assigned AKS managed identity.