Introduce a batch subscription mechanism in msgdispatcher: the
msgdispatcher now includes a vchannel watch task queue, where all
vchannels in the queue will subscribe to the MQ only once and pull
messages from the oldest vchannel checkpoint to the latest.
issue: https://github.com/milvus-io/milvus/issues/39862
pr: https://github.com/milvus-io/milvus/pull/39863
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Signed-off-by: bigsheeper <yihao.dai@zilliz.com>
1. Move the common modules of streamingNode and dataNode to flushcommon
2. Add new GetVChannels interface for rootcoord
issue: https://github.com/milvus-io/milvus/issues/33285
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Signed-off-by: bigsheeper <yihao.dai@zilliz.com>