[Dev UI] Support arbitrary model configuration parameters

[MichaelDoyle]

Currently we do not support model parameters that are not part of the common set. For the most part, this does not impact Gemini support outside of “safety” (see #689). It’s more noticeable with OpenAI and/or Anthropic, although most of these options are fairly niche.

This feature would dynamically render and bind form elements for any known configuration option.

Note: We also need to dynamically validate model configuration, which also applies to the standard configuration options. As an example, Open AI and Gemini have different ranges for temperature. This could be driven by the underlying schema definitions for each model.