Since there are two realized entities for subnet in
API policy/api/v1/infra/realized-state/realized-entities?intent_path=/infra/ip-pools/pool-1/ip-subnets/subnet-1,
sometimes we want to check the realization state for all entities.
Add all_results param in get_ip_subnet_realization_info func
to check all the entities realization state, and
return all the realized entities if no entity_type param set.
The default value for all_results is False.
Change-Id: I5a48c8f7e711090b38ea31d5f732f022bc7bd4bc
a62e5ad111