feat(knowledge): Add LLM document filtering processor #248

[kaysonx]

When submitting a PR, please confirm the following points and put [x] in the boxes one by one. | 在提出pr时，请确认了以下几点，并逐一使用[x]符号确认勾选。

Checklist | 检查项

• I have read and understood the contributor guidelines. | 我已阅读并理解贡献者指南 。
• I have checked for any duplicate features related to this request and communicated with the project maintainers. | 我已检查没有与此请求重复的功能并与项目维护者进行了沟通。
• I accept the suggestion of the maintainers to make changes to or close this PR. | 我接受此PR配合维护人员的建议进行修改或关闭。
• I have submitted the test files and can provide screenshots of the test results (required for feature or bug fixes) | 我已经提交了测试文件并可提供测试结果截图(功能修改、BUG修复类PR必须提供，其他按需)
• I have added or modified the documentation related to this PR | 我已经添加或修改了本次pr对应的文档说明(非必要，根据实际PR内容按需添加)
• I have added examples and notes if needed | 我已经添加了使用案例代码与文档说明(非必要，根据实际PR内容按需添加)

Please fill in the specific details of this PR: | 请详细填写本次PR的内容:
Added LLM document filtering processor that:
新增LLM文档过滤器:

• Add an LLM document filtering processor, which supports configuring various filtering rules through text.
  添加LLM文档过滤处理器，支持通过文本配置各种过滤规则
• Configurable LLM, rules, batch filtering size, and Prompt.
  可配置化的 LLM、规则、批量过滤条数以及Prompt
• Add unit tests and integration tests.
  添加单元测试及集成测试

Please provide the path of test files and submit screenshots or files of the test results(fill in as needed): | 请填写测试文件路径并提供测试结果截图或文件(按需填写):

• tests/test_agentuniverse/unit/agent/action/knowledge/doc_processor/test_llm_filter.py

- examples/sample_apps/rag_app/intelligence/test/test_llm_doc_filter.py

Please list the names of the docs that were added or modified in this PR (fill in as needed): | 请列出本次PR新增或修改的文档名称(按需填写):

• agentuniverse/agent/action/knowledge/doc_processor/llm_doc_filter.yaml

[kaysonx]

#248