Rename tensorflow namespace

modules/dnn/src/tensorflow/attr_value.proto

 syntax = "proto3";
 
-package tensorflow;
+package opencv_tensorflow;
 option cc_enable_arenas = true;
 option java_outer_classname = "AttrValueProtos";
 option java_multiple_files = true;

modules/dnn/src/tensorflow/function.proto

 syntax = "proto3";
 
-package tensorflow;
+package opencv_tensorflow;
 option cc_enable_arenas = true;
 option java_outer_classname = "FunctionProtos";
 option java_multiple_files = true;

modules/dnn/src/tensorflow/graph.proto

 syntax = "proto3";
 
-package tensorflow;
+package opencv_tensorflow;
 option cc_enable_arenas = true;
 option java_outer_classname = "GraphProtos";
 option java_multiple_files = true;

modules/dnn/src/tensorflow/op_def.proto

 syntax = "proto3";
 
-package tensorflow;
+package opencv_tensorflow;
 option cc_enable_arenas = true;
 option java_outer_classname = "OpDefProtos";
 option java_multiple_files = true;

modules/dnn/src/tensorflow/tensor.proto

 syntax = "proto3";
 
-package tensorflow;
+package opencv_tensorflow;
 option cc_enable_arenas = true;
 option java_outer_classname = "TensorProtos";
 option java_multiple_files = true;

modules/dnn/src/tensorflow/tensor_shape.proto

@@ -6,7 +6,7 @@ option java_outer_classname = "TensorShapeProtos";
 option java_multiple_files = true;
 option java_package = "org.tensorflow.framework";
 
-package tensorflow;
+package opencv_tensorflow;
 
 // Dimensions of a tensor.
 message TensorShapeProto {

modules/dnn/src/tensorflow/tf_io.hpp

@@ -26,6 +26,7 @@ Declaration of various functions which are related to Tensorflow models reading.
 #pragma GCC diagnostic pop
 #endif
 
+namespace tensorflow { using namespace opencv_tensorflow; }
 
 namespace cv {
 namespace dnn {

modules/dnn/src/tensorflow/types.proto

 syntax = "proto3";
 
-package tensorflow;
+package opencv_tensorflow;
 option cc_enable_arenas = true;
 option java_outer_classname = "TypesProtos";
 option java_multiple_files = true;

modules/dnn/src/tensorflow/versions.proto

 syntax = "proto3";
 
-package tensorflow;
+package opencv_tensorflow;
 option cc_enable_arenas = true;
 option java_outer_classname = "VersionsProtos";
 option java_multiple_files = true;