issue: #40638
- Add `ChannelID` for streaming replica in future.
- Remove the pchannel count fair balance policy for streaming.
- Add Score based vchannel fair balance policy for streaming.
- Add pchannel stats manager to collect the stats of pchannel for
balancer.
- Add configuration and metrics for new balance policy
---------
Signed-off-by: chyezh <chyezh@outlook.com>
issue: #37764
- add a local client to call local server directly for
querycoord/rootcoord/datacoord.
- enable local client if milvus is running mixcoord or standalone mode.
---------
Signed-off-by: chyezh <chyezh@outlook.com>