Sample prompts not displaying correctly

[DaltheCow]

Describe the bug
The sample prompts section should show prompt snippets used in the benchmark run. A recent update has changed some of the underlying code structure and now the request_args holds much more than the prompt. The prompt is not surfaced in the shown sample.

Visualized (this will go down eventually when the PR is closed): https://blog.vllm.ai/guidellm/ui/pr/427/

Expected behavior
Example of it working (this will go down eventually as well, but for now holds the previous working state) https://blog.vllm.ai/guidellm/ui/pr/391/

Additional context
The change comes from an update to what request_args holds in the benchmark report. Previously the UI data relied on request_args holding the prompt value, but now the prompt text is nested within. Something like: request_args.method.body.model.messages[0].content[0].text

See: https://github.com/vllm-project/guidellm/blob/main/src/guidellm/presentation/data_models.py#L120

[AiKiAi-stack]

Same issue with wrong location