API: Add Permissions fields to Model resource

According to the current API docs you can only *filter* /models using: allowNoCredit allowDerivatives allowDifferentLicenses allowCommercialUse It would be helpful for 3rd party services who are using the API to be able to store/query this information for individual models for the GET /api/v1/models/:modelId and :modelVersionId endpoints. Background: https://www.mage.space/ has imported all CivitAI models and are not abiding by allowNoCredit nor allowCommercialUse. It would be great if in future these fields had even greater visibility and more usefulness for generation services.