Fix: AzureChat model code (#8426)

### What problem does this PR solve?

- Simplify AzureChat constructor by passing base_url directly
- Clean up spacing and formatting in chat_model.py
- Remove redundant parentheses and improve code consistency
- #8423

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

rag/llm/chat_model.py

@@ -185,7 +185,6 @@ class Base(ABC):
                         except Exception as e:
                             history.append({"role": "tool", "tool_call_id": tool_call.id, "content": f"Tool call error: \n{tool_call}\nException:\n" + str(e)})
 
-
                 except Exception as e:
                     e = self._exceptions(e, attempt)
                     if e:
@@ -453,11 +452,11 @@ class DeepSeekChat(Base):
 
 
 class AzureChat(Base):
-    def __init__(self, key, model_name, **kwargs):
+    def __init__(self, key, model_name, base_url, **kwargs):
         api_key = json.loads(key).get("api_key", "")
         api_version = json.loads(key).get("api_version", "2024-02-01")
-        super().__init__(key, model_name, kwargs["base_url"], **kwargs)
-        self.client = AzureOpenAI(api_key=api_key, azure_endpoint=kwargs["base_url"], api_version=api_version)
+        super().__init__(key, model_name, base_url, **kwargs)
+        self.client = AzureOpenAI(api_key=api_key, azure_endpoint=base_url, api_version=api_version)
         self.model_name = model_name
 
 
@@ -925,10 +924,10 @@ class LocalAIChat(Base):
 
 
 class LocalLLM(Base):
-
     def __init__(self, key, model_name, base_url=None, **kwargs):
         super().__init__(key, model_name, base_url=base_url, **kwargs)
         from jina import Client
+
         self.client = Client(port=12345, protocol="grpc", asyncio=True)
 
     def _prepare_prompt(self, system, history, gen_conf):
@@ -985,13 +984,7 @@ class VolcEngineChat(Base):
 
 
 class MiniMaxChat(Base):
-    def __init__(
-        self,
-        key,
-        model_name,
-        base_url="https://api.minimax.chat/v1/text/chatcompletion_v2",
-        **kwargs
-    ):
+    def __init__(self, key, model_name, base_url="https://api.minimax.chat/v1/text/chatcompletion_v2", **kwargs):
         super().__init__(key, model_name, base_url=base_url, **kwargs)
 
         if not base_url:
@@ -1223,6 +1216,7 @@ class GeminiChat(Base):
 
     def _chat(self, history, gen_conf):
         from google.generativeai.types import content_types
+
         system = history[0]["content"] if history and history[0]["role"] == "system" else ""
         hist = []
         for item in history: