Add rag trace

[moria97]

1. 支持agentscope的opentelemetry schema
2. 支持trace 上下文传播和baggage后处理
3. 支持http endpoint埋点

[github-actions]

☂️ Python Coverage

current status: ✅

Overall Coverage

Lines	Covered	Coverage	Threshold	Status
12684	5211	41%	0%	🟢

New Files

File	Coverage	Status
backend/extensions/trace/baggage_processor.py	39%	🟢
backend/extensions/trace/http_exporter.py	37%	🟢
backend/extensions/trace/rag_wrapper.py	33%	🟢
backend/extensions/trace/trace_context_middleware.py	100%	🟢
TOTAL	52%	🟢

Modified Files

File	Coverage	Status
backend/app/main.py	84%	🟢
backend/common/tool/search_result.py	100%	🟢
backend/db/models/trace.py	94%	🟢
backend/extensions/trace/base.py	60%	🟢
backend/extensions/trace/pai_agent_wrapper.py	35%	🟢
backend/extensions/trace/trace_config.py	90%	🟢
backend/extensions/trace/tracer.py	46%	🟢
backend/rag/rerank/dashscope_reranker.py	52%	🟢
backend/rag/rerank/fusion_reranker.py	27%	🟢
backend/rag/rerank/reranker.py	21%	🟢
backend/service/knowledgebase/rag_service.py	44%	🟢
backend/service/tool/trace_service.py	41%	🟢
backend/tools/utils/vectordb_retrieval.py	61%	🟢
TOTAL	58%	🟢

updated for commit: 5233421 by action🐍