Rbac tests for Neutron list actions

Add RBAC tests for
    * list_routers [0]
    * list_subnetpools [1]
    * list_networks [2]
    * list_ports [3]
    * list_trunks [4]
    * list_address_scopes [5]
    * list_floatingips [6]
    * list_rbac_policies [8]
    * list_metering_labels [10]
    * list_metering_label_rules [11]
    * list_qos_policies [12]
    * list_dscp_marking_rules [13]
    * list_agents [14]
    * list_segments [15]

Update RBAC tests to use validate_list function for:
    * list_subnets [7]
    * list_security_groups [9]

[0] https://developer.openstack.org/api-ref/network/v2/index.html#list-routers
[1] https://developer.openstack.org/api-ref/network/v2/index.html#list-subnet-pools
[2] https://developer.openstack.org/api-ref/network/v2/index.html#list-networks
[3] https://developer.openstack.org/api-ref/network/v2/index.html#list-ports
[4] https://developer.openstack.org/api-ref/network/v2/index.html#list-trunks
[5] https://developer.openstack.org/api-ref/network/v2/index.html#list-address-scopes
[6] https://developer.openstack.org/api-ref/network/v2/index.html#list-floating-ips
[7] https://developer.openstack.org/api-ref/network/v2/index.html#list-subnets
[8] https://developer.openstack.org/api-ref/network/v2/index.html#list-rbac-policies
[9] https://developer.openstack.org/api-ref/network/v2/index.html#list-security-groups
[10] https://developer.openstack.org/api-ref/network/v2/index.html#list-metering-labels
[11] https://developer.openstack.org/api-ref/network/v2/index.html#list-metering-label-rules
[12] https://developer.openstack.org/api-ref/network/v2/index.html#list-qos-policies
[13] https://developer.openstack.org/api-ref/network/v2/index.html#list-dscp-marking-rules-for-qos-policy
[14] https://developer.openstack.org/api-ref/network/v2/index.html#list-all-agents
[15] https://developer.openstack.org/api-ref/network/v2/index.html#list-segments

Change-Id: I0dae01a3271efe6d3469718976c471416279e337
16 files changed