Evaluation: Tracking overall latency

[PritamSGB]

Is your feature request related to a problem?
We lack visibility on the overall evaluation process latency, which affects our ability to identify bottlenecks and optimize performance.

Describe the solution you'd like

• Track overall evaluation latency
• Breakdown latency for cosine score and LLM judge score
• Identify latency added by kaapi
• Explore scope for improvement in latency

Original issue

Tracking below for fast evals (observability)

• Tracking Evals overall latency
• Breakup for latency for cosine score, latency for llm judge score
• Latency added by kaapi ?

Basis above, explore scope for improvement on the latency