Add UDP test scenario

Update test_healthmonitor_traffic & test_basic_traffic tests
to support UDP traffic in test_traffic_ops
Add simple UDP test in test_ipv6_traffic_ops

Add a UDP test server, merged with the existing HTTP test server.

Change-Id: I1e497b75672753ed0e7acf482bc0e4a6138d3437
diff --git a/releasenotes/notes/add-udp-test-scenario-cdd131d1ef7bf8e9.yaml b/releasenotes/notes/add-udp-test-scenario-cdd131d1ef7bf8e9.yaml
new file mode 100644
index 0000000..2d1952d
--- /dev/null
+++ b/releasenotes/notes/add-udp-test-scenario-cdd131d1ef7bf8e9.yaml
@@ -0,0 +1,4 @@
+---
+features:
+  - |
+    Added test scenarios for UDP traffic.