openstack/openstack-ansible-os_neutron

OVN plumbing overhaul. The bulk of the week reshapes how the role manages OVS and OVN. setup_ovs_ovn was folded into ovn_config, ovn-central parameters are now statically provisioned, OVS bridge actions and OVN service actions are grouped into their own blocks, and direct ovs-vsctl invocations were swapped out for the openvswitch_db module. Operators also get a hook to override supplied external_ids during OVN setup, and DB connections now use management_address.

Cluster lifecycle. Two related additions harden cluster changes: an upgrade-time sweep that ensures no orphaned OVN members remain, and an OVN DB repair path when a new cluster is formed. A stale workaround for an ovs bug that reset hostnames on add was reverted.

Config surface. Individual Neutron quota variables were collapsed into a single mapping, VMware NSX-specific config and the neutron_api_workers variable were dropped, and pip package definitions moved to the Direct URL syntax.

Elsewhere, the change set came almost entirely from two contributors, with a small drive-by dropping deprecated NSX config.