fix: de-duplicating check using interface name

[ANISH-SR]

Summary of Changes

• CreateDeviceInterfaceCommand: Added a client-side duplicate-interface check in execute().
• If device.find_interface(&self.name).is_ok(), the command now returns an error and does not send the CreateDeviceInterface transaction.
• Extended test imports to include required interface types.
• Added test_commands_device_create_interface_command_duplicate_name_fails, which:
  • Builds a Device containing an existing "Ethernet0" interface.
  • Mocks client.get(device_pubkey) to return this device.
  • Asserts that executing the command with "Ethernet0" returns an error.

Testing Verification

• rust tests all green

fixes #2243

[Copilot]

Pull request overview

This PR adds client-side validation to prevent duplicate interface names when creating device interfaces. The change introduces an early check that returns an error if an interface with the same name already exists, avoiding unnecessary transaction execution.

Key changes:

• Added duplicate interface name validation in CreateDeviceInterfaceCommand::execute()
• Extended test imports to support comprehensive duplicate-name testing
• Added new test case verifying duplicate interface names are rejected

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