Feat: message manage (#12196)

### What problem does this PR solve?

Manage message and use in agent.

Issue #4213 

### Type of change

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

graphrag/search.py

@@ -24,11 +24,11 @@ from common.misc_utils import get_uuid
 from graphrag.query_analyze_prompt import PROMPTS
 from graphrag.utils import get_entity_type2samples, get_llm_cache, set_llm_cache, get_relation
 from common.token_utils import num_tokens_from_string
-from rag.utils.doc_store_conn import OrderByExpr
 
 from rag.nlp.search import Dealer, index_name
 from common.float_utils import get_float
 from common import settings
+from common.doc_store.doc_store_base import OrderByExpr
 
 
 class KGSearch(Dealer):