feat: support multi unit in trace config

[AnnaYue]

What is the purpose of the change

support multi unit in trace config

Brief changelog

When init trace intercepter for multi unit, trace client init with default unit name and instance name, cause generate same clientID for different unit server, but serverUrl resolved with different IPs, lead to client loadOrStore return nil and finally nil pointer crash.
So add UnitName param in traceConfig to allow unit name pass down.

Verifying this change

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