Implement model structured output, and add model test

[qbc2016]

AgentScope Version

1.0.0

Description

As the title says.

Checklist

Please check the following items before code is ready to be reviewed.

• Code has been formatted with pre-commit run --all-files command
• All tests are passing
• Docstrings are in Google style
• Related documentation has been updated (e.g. links, examples, etc.)
• Code is ready for review

[Copilot]

Pull Request Overview

This PR implements model structured output functionality and adds comprehensive model tests for multiple chat model implementations including OpenAI, Ollama, Gemini, DashScope, and Anthropic.

Key changes:

• Added structured_model parameter to all chat models to enable structured output generation using Pydantic BaseModel schemas
• Added metadata field to ChatResponse class to store structured output data
• Implemented comprehensive unit tests for all model classes covering various scenarios including streaming, tool usage, and structured output

Reviewed Changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/model_openai_test.py	Complete test suite for OpenAI chat model
tests/model_ollama_test.py	Complete test suite for Ollama chat model
tests/model_gemini_test.py	Complete test suite for Gemini chat model
tests/model_dashscope_test.py	Complete test suite for DashScope chat model
tests/model_anthropic_test.py	Complete test suite for Anthropic chat model
src/agentscope/model/_model_response.py	Added metadata field to ChatResponse class
src/agentscope/model/_openai_model.py	Implemented structured output support for OpenAI models
src/agentscope/model/_ollama_model.py	Implemented structured output support for Ollama models
src/agentscope/model/_gemini_model.py	Implemented structured output support for Gemini models
src/agentscope/model/_dashscope_model.py	Implemented structured output support for DashScope models
src/agentscope/model/_anthropic_model.py	Implemented structured output support for Anthropic models
src/agentscope/_utils/_common.py	Added utility function to create tools from Pydantic BaseModel
.github/workflows/unittest.yml	Updated CI to use dev dependencies instead of full

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[DavdGao]

Please see inline comments, and remove the unnecessary unittests to keep the code clean and tidy

[DavdGao]

lgtm