Initial detection for huawei gpon MDU (#9733)

* added initial detection for huawei gpon MDU

* Add files via upload

* Add files via upload

* Fixed tests

includes/definitions/smartax-mdu.yaml

@@ -0,0 +1,15 @@
+os: smartax-mdu
+group: huawei
+text: 'Huawei SmartAX MDU'
+type: network
+icon: huawei
+ifname: true
+nobulk: true
+over:
+    - { graph: device_bits, text: 'Device Traffic' }
+    - { graph: device_processor, text: 'CPU Usage' }
+discovery:
+    - sysObjectID:
+        - .1.3.6.1.4.1.2011.2.185
+mib_dir:
+   - huawei