What problem is the feature used to solve?

Currently, proto server code generation only supports built-in templates, which cannot satisfy the personalized requirements of different teams or projects regarding code structure and content.

Requirements description of the feature

• Add custom template support to the proto server generator.
• Allow specifying the path to a custom template file via parameters.
• Implement template loading logic, enabling users to generate code from custom files or use the default template.
• Modify the server-side code generation process to support custom templates.

References

• Related PR: feat(server): 为 proto server生成添加自定义模板支持

This issue is associated with the above PR and aims to track the requirements and progress of the custom template feature.