feat: add streaming output for studio

[lokidundun]

AgentScope-Java Version

1.0.8
[The version of AgentScope-Java you are working on, e.g. 1.0.7, check your pom.xml dependency version or run mvn dependency:tree | grep agentscope-parent:pom(only mac/linux)]

Description

[Please describe the background, purpose, changes made, and how to test this PR]
Feat #416

Checklist

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

• Code has been formatted with mvn spotless:apply
• All tests are passing (mvn test)
• Javadoc comments are complete and follow project conventions
• Related documentation has been updated (e.g. links, examples, etc.)
• Code is ready for review

[cla-assistant]

All committers have signed the CLA.

[cla-assistant]

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[codecov]

Codecov Report

❌ Patch coverage is 75.36232% with 17 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...a/io/agentscope/core/studio/StudioMessageHook.java	75.36%	12 Missing and 5 partials ⚠️

📢 Thoughts on this report? Let us know!

[AlbumenJ]

@zhijianma PTAL