Add OTG automated tests with RPYC server (New)

[stanley31huang]

Description

Add OTG automated tests with RPYC server (New)
there are following changes made in this PR

• modified serial_test.py to fit to the otg testing
• rpyc_server.py
• rpyc_client.py
• rpyc_test_methods.py
• multiple_otg.py

Documentation

N/A

Tests

I have build a test snap locally and tested it on an IoT device
Noted: the OTG feature seems not working on this device in post-suspend stage.
https://certification.canonical.com/hardware/202312-33702/submission/407861/

[baconYao]

Please see my comments

[baconYao]

LGTM

[stanley31huang]

fixed the conflict issues.

[rickwu666666]

LGTM

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 49.01%. Comparing base (e5b7c6f) to head (798ed13).
Report is 125 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1678   +/-   ##
=======================================
  Coverage   49.01%   49.01%           
=======================================
  Files         372      372           
  Lines       40348    40348           
  Branches     6817     6817           
=======================================
  Hits        19777    19777           
  Misses      19849    19849           
  Partials      722      722           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.