Changes to Generate a message (Anthropic-compatible)

added the non-success response with the status 403

added the optional property error/allowed_models_hint to the response with the 400 status

added the optional property error/allowed_models_hint to the response with the 401 status

added the optional property error/allowed_models_hint to the response with the 402 status

added the optional property error/allowed_models_hint to the response with the 413 status

added the optional property error/allowed_models_hint to the response with the 429 status

added the optional property error/allowed_models_hint to the response with the 503 status

added the optional property error/denied_by to the response with the 400 status

added the optional property error/denied_by to the response with the 401 status

added the optional property error/denied_by to the response with the 402 status

added the optional property error/denied_by to the response with the 413 status

added the optional property error/denied_by to the response with the 429 status

added the optional property error/denied_by to the response with the 503 status

added the optional property error/model to the response with the 400 status

added the optional property error/model to the response with the 401 status

added the optional property error/model to the response with the 402 status

added the optional property error/model to the response with the 413 status

added the optional property error/model to the response with the 429 status

added the optional property error/model to the response with the 503 status

added the optional property error/param to the response with the 400 status

added the optional property error/param to the response with the 401 status

added the optional property error/param to the response with the 402 status

added the optional property error/param to the response with the 413 status

added the optional property error/param to the response with the 429 status

added the optional property error/param to the response with the 503 status

added the optional property error/permission to the response with the 400 status

added the optional property error/permission to the response with the 401 status

added the optional property error/permission to the response with the 402 status

added the optional property error/permission to the response with the 413 status

added the optional property error/permission to the response with the 429 status

added the optional property error/permission to the response with the 503 status

endpoint added