milvus: [Bug]: EtcdKV CompareAndSwap interface semantic is confused

Is there an existing issue for this?

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Environment

- Milvus version:
- Deployment mode(standalone or cluster):
- SDK version(e.g. pymilvus v2.0.0rc2):
- OS(Ubuntu or CentOS): 
- CPU/Memory: 
- GPU: 
- Others:

Current Behavior

etcdKV support compareAndSwap by value and version, if compare failed it will throw NewCompareFailedError.

Expected Behavior

1. compareAndSwap should support idempotent retry.
2. if version or value mismatch, should return true/false rather than direct return error

Steps To Reproduce

No response

Anything else?

No response