This commit introduces minimal service settings in the model registry, accessible without querying the inference index.
These settings are now available for the default models exposed by the inference service.

The ability to access settings without an inference index query is needed for the semantic text field, as it would benefit from eager validation of configuration during field creation.
This is not feasible currently because retrieving service settings relies on an asynchronous call to the inference index.

### Follow-Up Plans:
1. Extend this capability to include minimal service settings for all newly added models, making them accessible via the cluster state.
2. Update the semantic text field to eagerly retrieve service settings directly from the model registry.