Added ResizeBilinear op for tf (#11050)

* Added ResizeBilinear op for tf

Combined ResizeNearestNeighbor and ResizeBilinear layers into Resize (with an interpolation param).

Minor changes to tf_importer and resize layer to save some code lines

Minor changes in init.cpp

Minor changes in tf_importer.cpp

* Replaced implementation of a custom ResizeBilinear layer to all layers

* Use Mat::ptr. Replace interpolation flags

samples/dnn/text_detection.cpp

@@ -2,8 +2,6 @@
 #include <opencv2/highgui.hpp>
 #include <opencv2/dnn.hpp>
 
-#include "custom_layers.hpp"
-
 using namespace cv;
 using namespace cv::dnn;
 
@@ -38,9 +36,6 @@ int main(int argc, char** argv)
     CV_Assert(parser.has("model"));
     String model = parser.get<String>("model");
 
-    // Register a custom layer.
-    CV_DNN_REGISTER_LAYER_CLASS(ResizeBilinear, ResizeBilinearLayer);
-
     // Load network.
     Net net = readNet(model);