Feat: Implement the runtime visualization of the benchmark

[nvzhihanj]

Runtime visualization is key to a successful endpoint benchmarking tool. Define the interface and functionality for:

• "Real-time" performance and latency visualization (quoted because we can tolerate latency)
• Low-overhead integration with the current software such that the main process will not be burdened

Reference:

• vLLM Grafana
• AIPerf dashboard
• SGLang GenAI Perf