### What this PR does / why we need it?
pd disaggregated support cross-machine.
We send the primary and secondary node information of node p to node d.
When node d pulls the KV data, it retrieves the corresponding primary or
secondary node information from the mapping.
- vLLM version: v0.12.0
- vLLM main:
ad32e3e19c
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Signed-off-by: weiguihua2 <weiguihua2@huawei.com>