Implement CLI for OTBR with NCP

[yangsong-cnyn]

This issue tracks the process of implementing a CLI for OTBR running under NCP mode.

Background:

In the OTBR architecture with an NCP, the OpenThread Core resides on the NCP, while the OTBR service, including the CLI application, remains on the Host. To enable CLI functionality for managing the OTBR, we need to establish communication between the CLI and the OpenThread Core using the Spinel protocol. This will allow for command and output transfer between the two components.

Proposed Implementation:

• Move the CLI daemon from OpenThread posix to OTBR host posix for command receiving

• Extend the Spinel communication on the OTBR CLI daemon and implement corresponding handling of these CLI commands within the NCP.

• Include the existing CLI interpreter module into NCP

• Ensure seamless command translation and output formatting between host and the NCP Core, for both sync and async commands

Benefits:

• Provides a familiar interface for user to interact with and manage OTBR with NCP, which enables easier debugging and troubleshooting with the CLI

Tasks and PRs:

• Move the CLI daemon from OpenThread posix to OTBR host posix
  [posix] Add Cli Daemon module #2676