Add support for managing network segments

Adds a module to manage Neutron network segments where the
segmentation plugin is enabled.

Segments are relatively simple and do not support modification
beyond the name/description, so most attributes are used for
initial segment creation, or filtering results in order to
perform updates.

Depends-On: https://review.opendev.org/c/openstack/ansible-collections-openstack/+/955752
Change-Id: I4647fd96aaa15460d82765365f98a18ddf2693db

ci/roles/network_segment/defaults/main.yml

@@ -0,0 +1,17 @@
+---
+expected_fields:
+  - description
+  - id
+  - name
+  - network_id
+  - network_type
+  - physical_network
+  - segmentation_id
+
+network_name: segment_network
+segment_name: example_segment
+network_type: vlan
+segmentation_id: 999
+physical_network: public
+initial_description: "example segment description"
+updated_description: "updated segment description"