issue #42492
- streamingcoord start before old rootcoord.
- streaming balancer will check the node session synchronously to avoid
redundant operation when cluster startup.
- ddl operation will check if streaming enabled, if the streaming is not
enabled, it will use msgstream.
- msgstream will initialize if streaming is not enabled, and stop when
streaming is enabled.
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Signed-off-by: chyezh <chyezh@outlook.com>