Adding workload generator that converts internal workload traces.

### 🚀 Feature Description and Motivation

Adding a workload generator that generate workload file based on internal workload trace format (e.g., csv file).

### Use Case

The generator should support converting load traces to unified workload format, which later on consumed by AIBrix client to generate real-world workloads.

### Proposed Solution

Adding a generator that incorporates different adapter to convert trace files into LLM request workloads format. This issue tracks the converter of internal traces.