Add missing tempest client for "QoS Limit Bandwidth" APIs + testing

"QoS Limit Bandwidth" APIs must be used in Octavia-Tempest-Plugin
to add missing QoS based tests.

Note: this patch fixes the "expected status" code for
Update Minimum Bandwidth, that was set to default 200 instead of 202.

Change-Id: I30d9d823c972e560a0a48e24e44fb16bcc353c5a
diff --git a/releasenotes/notes/add-qos-apis-for-bandwidth-limit-rules-cc144660fcaa419a.yaml b/releasenotes/notes/add-qos-apis-for-bandwidth-limit-rules-cc144660fcaa419a.yaml
new file mode 100644
index 0000000..da58ba3
--- /dev/null
+++ b/releasenotes/notes/add-qos-apis-for-bandwidth-limit-rules-cc144660fcaa419a.yaml
@@ -0,0 +1,11 @@
+---
+features:
+  - |
+    Add "QoS bandwidth limit rules" APIs to:
+    "tempest/tests/lib/services/network/test_qos_limit_bandwidth_rules_client.py"  module.
+
+    * List bandwidth limit rules for QoS policy
+    * Create bandwidth limit rule
+    * Show bandwidth limit rule details
+    * Update bandwidth limit rule
+    * Delete bandwidth limit rule
\ No newline at end of file