[plugin] Custom model_runner/model support (#3186)

* support custom model&&model_runner

* fix merge

* add test && update doc

* fix codestyle

* fix unittest

* load model in rl

fastdeploy/model_executor/layers/attention/attention.py

@@ -48,6 +48,7 @@ class Attention(nn.Layer):
         linear_shift: paddle.Tensor = None,
         linear_smooth: paddle.Tensor = None,
         use_neox_rotary_style: bool = False,
+        use_qk_norm: bool = False,
     ) -> None:
         """
         Initializes `LMLayer` with the given parameters.