Add shutdown command to H3C interface template and update related configuration files

- Included the `shutdown` command in the H3C interface template to reflect the new interface state management.
- Updated the `config.conf` file to include the `shutdown` command for the `HundredGigE1/0/3` interface.
- Modified the expected output JSON to set the `shutdown` attribute to true, ensuring accurate testing and validation of interface configurations.

tests/fixtures/h3c/config.conf

@@ -152,6 +152,7 @@ interface HundredGigE1/0/3
  port link-type trunk
  undo port trunk permit vlan 1
  port trunk permit vlan 221 1112 to 1116 1512
+ shutdown
  storm-constrain broadcast pps 1100 1000
  storm-constrain multicast pps 1100 1000
  storm-constrain control shutdown