Fix and refactor imports (#11010)

### What problem does this PR solve?

1. Move EMBEDDING_CFG to common.globals
2. Fix error imports
3. Move signal handles to common/signal_utils.py

### Type of change

- [x] Refactoring

---------

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

api/db/services/llm_service.py

@@ -30,13 +30,14 @@ class LLMService(CommonService):
 
 def get_init_tenant_llm(user_id):
     from api import settings
+    from common import globals
     tenant_llm = []
 
     seen = set()
     factory_configs = []
     for factory_config in [
         settings.CHAT_CFG,
-        settings.EMBEDDING_CFG,
+        globals.EMBEDDING_CFG,
         settings.ASR_CFG,
         settings.IMAGE2TEXT_CFG,
         settings.RERANK_CFG,

api/db/services/tenant_llm_service.py

@@ -17,6 +17,7 @@ import os
 import logging
 from langfuse import Langfuse
 from api import settings
+from common import globals
 from common.constants import LLMType
 from api.db.db_models import DB, LLMFactories, TenantLLM
 from api.db.services.common_service import CommonService
@@ -114,7 +115,7 @@ class TenantLLMService(CommonService):
         if model_config:
             model_config = model_config.to_dict()
         elif llm_type == LLMType.EMBEDDING and fid == 'Builtin' and "tei-" in os.getenv("COMPOSE_PROFILES", "") and mdlnm == os.getenv('TEI_MODEL', ''):
-            embedding_cfg = settings.EMBEDDING_CFG
+            embedding_cfg = globals.EMBEDDING_CFG
             model_config = {"llm_factory": 'Builtin', "api_key": embedding_cfg["api_key"], "llm_name": mdlnm, "api_base": embedding_cfg["base_url"]}
         else:
             raise LookupError(f"Model({mdlnm}@{fid}) not authorized")