device lock/unlock and account lock/unlock commands and sdk examples

[mtyagi-ks]

Extend device management with lock, unlock, account-lock, and
account-unlock actions to match Commander device-user-action support.

SDK:

• Add lock_user_devices, unlock_user_devices, account_lock_user_devices,
  and account_unlock_user_devices in device_management.py
• Reuse existing _execute_device_action() with DA_LOCK, DA_UNLOCK,
  DA_DEVICE_ACCOUNT_LOCK, and DA_DEVICE_ACCOUNT_UNLOCK action types

CLI:

• Add device-lock, device-unlock, device-account-lock, and
  device-account-unlock commands
• Refactor remove/logout to shared _run_device_action_command() helper
• Register new commands in register_commands.py

Examples:

• Add lock_device.py, unlock_device.py, account_lock_device.py, and
  account_unlock_device.py under examples/sdk_examples/device_management/

Tests:

• Add unit tests for lock_user_devices and account_unlock_user_devices