Move cpp code to directory csrcs (#42)

* move cpp code to csrcs

* move cpp code to csrcs

fastdeploy/backends/backend.h

@@ -1,48 +0,0 @@
-// Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#pragma once
-
-#include <iostream>
-#include <memory>
-#include <string>
-#include <vector>
-#include "fastdeploy/backends/common/multiclass_nms.h"
-#include "fastdeploy/core/fd_tensor.h"
-
-namespace fastdeploy {
-
-struct TensorInfo {
-  std::string name;
-  std::vector<int> shape;
-  FDDataType dtype;
-};
-
-class BaseBackend {
- public:
-  bool initialized_ = false;
-
-  BaseBackend() {}
-
-  virtual bool Initialized() const { return initialized_; }
-
-  virtual int NumInputs() const = 0;
-  virtual int NumOutputs() const = 0;
-  virtual TensorInfo GetInputInfo(int index) = 0;
-  virtual TensorInfo GetOutputInfo(int index) = 0;
-  virtual bool Infer(std::vector<FDTensor>& inputs,
-                     std::vector<FDTensor>* outputs) = 0;
-};
-
-}  // namespace fastdeploy