Feature Request: Make defaultObjectGenerationMode and supportsStructuredOutputs configurable

[ArnoChenFx]

Make defaultObjectGenerationMode and supportsStructuredOutputs configurable to support more models.

For example:

• gpt-4o: defaultObjectGenerationMode='json' and supportsStructuredOutputs=false
• mistral-small-24b-instruct-2501 in lm-studio: defaultObjectGenerationMode='json' and supportsStructuredOutputs=true
• deepseek-v3: defaultObjectGenerationMode='json' and supportsStructuredOutputs=false
• deepseek-v3 in silliconflow: defaultObjectGenerationMode='tool' and supportsStructuredOutputs=false