feat: support streaming rendering of Mermaid charts

[zhu-xiaowei]

Description

1. support streaming rendering of Mermaid charts

General Checklist

• The code changes have been fully tested
• Security oriented best practices and standards are followed (e.g. using input sanitization, principle of the least privilege, etc.)
• Documentation update for the change if required
• PR title conforms to conventional commit style
• If breaking change, documentation/changelog update with migration instructions

By submitting this pull request, I confirm that my contribution is made under the terms of the MIT-0 license.