issue: #35821
After collection loaded, if we need to increase/decrease collection's
replica, we need to release and load it again.
milvus offers 4 solution to update loaded collection's replica, this PR
aims to dynamic change the replica number without release, and after
replica number changed, milvus will execute load replica or release
replica in async, and the replica loaded status can be checked by
getReplicas API.
Notice that if set too much replicas than querynode can afford，the new
replica won't be loaded successfully until enough querynode joins.
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Signed-off-by: Wei Liu <wei.liu@zilliz.com>
