[Tooling] Add evals for prompts

[shrutip90]

UI > dotprompt > for model config.

Open questions:
Should we show the rendered prompt or input values in evals?
INPUT VALUES, with the rendered template somewhere (not the current one, but the one we sent to the model)

[ssbushi]

@mjchristy We need to finalize how we want to show templates (or rendered templates) in eval results for prompts

[ssbushi]

UX for prompt results.