[WIP] Add CPP Servicer

[chenyushuo]

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name: Add CPP Servicer about: Add CPP Servicer

Description

Rerewrite Servicer with CPP.

Checklist

Please check the following items before code is ready to be reviewed.

• [ ] Code has passed all tests
• [ ] Docstrings have been added/updated in Google Style
• [ ] Documentation has been updated
• [ ] Code is ready for review