Optimize get_ports with QoS extension
Optimize get_ports with QoS extension

Apply qos resource extend func for a full list of ports,
not for each port individually, thus avoiding DB queries for each
individual port.
This should drastically improve port list time in case of many
ports/network with QoS policies assigned.

Change-Id: I1d0b3975ae6e92e34e9da20a0e26ce024422d332
Closes-Bug: #1905726

mahak/neutron,mahak/neutron,openstack/neutron,openstack/neutron,mahak/neutron,openstack/neutron