Merge pull request #12264 from dkurt:dnn_remove_forward_method

* Remove a forward method in dnn::Layer

* Add a test

* Fix tests

* Mark multiple dnn::Layer::finalize methods as deprecated

* Replace back dnn's inputBlobs to vector of pointers

* Remove Layer::forward_fallback from CV_OCL_RUN scopes

modules/dnn/misc/python/pyopencv_dnn.hpp

@@ -146,16 +146,16 @@ public:
         return false;
     }
 
-    virtual void forward(std::vector<Mat*> &inputs, std::vector<Mat> &outputs, std::vector<Mat> &) CV_OVERRIDE
+    virtual void forward(InputArrayOfArrays inputs_arr, OutputArrayOfArrays outputs_arr, OutputArrayOfArrays) CV_OVERRIDE
     {
         PyGILState_STATE gstate;
         gstate = PyGILState_Ensure();
 
-        std::vector<Mat> inps(inputs.size());
-        for (size_t i = 0; i < inputs.size(); ++i)
-            inps[i] = *inputs[i];
+        std::vector<Mat> inputs, outputs;
+        inputs_arr.getMatVector(inputs);
+        outputs_arr.getMatVector(outputs);
 
-        PyObject* args = pyopencv_from(inps);
+        PyObject* args = pyopencv_from(inputs);
         PyObject* res = PyObject_CallMethodObjArgs(o, PyString_FromString("forward"), args, NULL);
         Py_DECREF(args);
         PyGILState_Release(gstate);
@@ -174,11 +174,6 @@ public:
         }
     }
 
-    virtual void forward(InputArrayOfArrays, OutputArrayOfArrays, OutputArrayOfArrays) CV_OVERRIDE
-    {
-        CV_Error(Error::StsNotImplemented, "");
-    }
-
 private:
     // Map layers types to python classes.
     static std::map<std::string, std::vector<PyObject*> > pyLayers;