serial-console: decode binary WebSocket frames before printing

[praveen-pk]

websocket-client delivers binary frames as Python bytes objects. Passing bytes directly to PC.print() causes print() to render them as raw repr strings (e.g. b'\r\r\n', b'login: ') instead of decoded text, which corrupts the serial console output in WSL and other non-Windows environments.

Fix this by decoding bytes to str with UTF-8 (replacing invalid sequences) in on_message() before calling PC.print().

Fixes: Azure/azure-cli#33164

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Thanks for your contribution!

[azure-client-tools-bot-prd]

Hi @praveen-pk,
Please write the description of changes which can be perceived by customers into HISTORY.rst.
If you want to release a new extension version, please update the version in setup.py as well.

[yonzhan]

Thank you for your contribution! We will review the pull request and get back to you soon.

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[Copilot]

Pull request overview

This PR fixes corrupted Azure Serial Console output on non-Windows environments (e.g., WSL) by decoding binary WebSocket frames (Python bytes) into UTF-8 text before printing them to the console.

Changes:

• Decode bytes WebSocket messages using UTF-8 with errors='replace' before calling PC.print().