【Feature】add fd plugins && rm model_classes (#3123)

* add fd plugins && rm model_classed

* fix reviews

* add docs

* fix

* fix unitest ci

fastdeploy/model_executor/models/qwen2.py

@@ -355,6 +355,10 @@ class Qwen2PretrainedModel(PretrainedModel):
         """
         return None
 
+    @classmethod
+    def arch_name(self):
+        return "Qwen2ForCausalLM"
+
     @classmethod
     def _get_tensor_parallel_mappings(cls, config: ModelConfig, is_split=True):