refactor: Refactor proxy LLM (#1064)

dbgpt/model/parameter.py

@@ -475,6 +475,16 @@ class ProxyModelParameters(BaseModelParameters):
     max_context_size: Optional[int] = field(
         default=4096, metadata={"help": "Maximum context size"}
     )
+    llm_client_class: Optional[str] = field(
+        default=None,
+        metadata={
+            "help": "The class name of llm client, such as dbgpt.model.proxy.llms.proxy_model.ProxyModel"
+        },
+    )
+
+    def __post_init__(self):
+        if not self.proxy_server_url and self.proxy_api_base:
+            self.proxy_server_url = f"{self.proxy_api_base}/chat/completions"
 
 
 @dataclass