Move some constants to common (#11004)

### What problem does this PR solve?

As title.

### Type of change

- [x] Refactoring

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

agent/component/categorize.py

@@ -18,7 +18,7 @@ import os
 import re
 from abc import ABC
 
-from api.db import LLMType
+from common.constants import LLMType
 from api.db.services.llm_service import LLMBundle
 from agent.component.llm import LLMParam, LLM
 from common.connection_utils import timeout

agent/component/llm.py

@@ -21,7 +21,7 @@ from copy import deepcopy
 from typing import Any, Generator
 import json_repair
 from functools import partial
-from api.db import LLMType
+from common.constants import LLMType
 from api.db.services.llm_service import LLMBundle
 from api.db.services.tenant_llm_service import TenantLLMService
 from agent.component.base import ComponentBase, ComponentParamBase

agent/tools/retrieval.py

@@ -19,7 +19,7 @@ import os
 import re
 from abc import ABC
 from agent.tools.base import ToolParamBase, ToolBase, ToolMeta
-from api.db import LLMType
+from common.constants import LLMType
 from api.db.services.document_service import DocumentService
 from api.db.services.dialog_service import meta_filter
 from api.db.services.knowledgebase_service import KnowledgebaseService