Add component Concentrator (#2586)

### What problem does this PR solve?

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

agent/component/__init__.py

@@ -9,6 +9,7 @@ from .relevant import Relevant, RelevantParam
 from .message import Message, MessageParam
 from .rewrite import RewriteQuestion, RewriteQuestionParam
 from .keyword import KeywordExtract, KeywordExtractParam
+from .concentrator import Concentrator, ConcentratorParam
 from .baidu import Baidu, BaiduParam
 from .duckduckgo import DuckDuckGo, DuckDuckGoParam
 from .wikipedia import Wikipedia, WikipediaParam