[Bug]: Querycoord set wrong watchDmchannelInfo when one partition is empty

[xige-16]

Is there an existing issue for this?

• I have searched the existing issues

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

If a collection has multi partitions, and some some partitions don't have been inserted. There may be two problems when loading：

1. If some paritiotns have not been inserted, the checkpoint of the partitions has not been updated, resulting in the seekposition in the watchchannelReq received by the querynode being an older checkpoint. Then load will be slower

2. the flushed segment list in the watchchannelReq received by the querynode are empty

Eventually, when loading, for a certain segment, querynode memory exists both the seal segment and the growing segnent, So the memory needed when loading will be double.

After the load is completed, the querynode will delete the growing segment from memory after receiving the sealedsegmentchangeinfo, and eventually the querynode memory will only have the sealed segments.

Expected Behavior

No response

Steps To Reproduce

No response

Anything else?

No response

[xige-16]

/unassign @yanliang567
/unassign

[xige-16]

/assign