Add shutdown command to Huawei interface template and update configuration files

- Included the `shutdown` command in the Huawei interface template to manage interface states.
- Added a new interface configuration in `config.conf` with the `shutdown` command.
- Updated the expected output JSON to reflect the new interface and its shutdown state for accurate testing and validation of configurations.

tests/fixtures/huawei/config.expected.json

@@ -12,6 +12,13 @@
       "mask": null,
       "description": null
     },
+    {
+      "interface": "GigabitEthernet1/0/43",
+      "shutdown": true,
+      "ip_address": null,
+      "mask": null,
+      "description": "FREE"
+    },
     {
       "interface": "Vlanif120",
       "shutdown": false,