How to set the downstream cluster info in spans reported by a waypoint

[fnless]

Please provide an in-depth description of the question you have:
We found that spans reported by a waypoint does not contain downstream info, like service name. I think the downstream info is very important for querying traces.

What do you think about this question?:
Is there anyway (like inject headers) to let waypoint know the remote service?
The kmesh_tcp_sent_bytes_total metric contains source_app label. So I think we can get the downstream info and do some hacks in the ebpf. Maybe there are better solutions.

Environment:

• Kmesh version: v1.1.0
• Kmesh mode(kmesh has Kernel-Native Mode and Dual-Engine Mode): Dual-Engine
• Istio version: 1.26.0
• Kernel version: 5.15.0-130-generic
• Others: