Asynchronous API from Intel's Inference Engine (#13694)
* Add forwardAsync for asynchronous mode from Intel's Inference Engine
* Python test for forwardAsync
* Replace Future_Mat to AsyncMat
* Shadow AsyncMat
* Isolate InferRequest callback
* Manage exceptions in Async API of IE
* 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
* Added the imagesFromBlob method to the dnn module.
* Rewritten imagesFromBlob based on first dkurt comments
* Updated code with getPlane()
* Modify comment of imagesFromBlob() in dnn module
* modified comments, removed useless assertions & added OutputArrayOfArray
* replaced tabs with whitespaces & put vectorOfChannels instantiation outside the loop
* Changed pre-commit.sample to pre-commit in .git/hooks/
* Added a test for imagesFromBlob in test_misc.cpp (dnn)
* Changed nbOfImages, robustified test with cv::randu, modified assertion
- removed tr1 usage (dropped in C++17)
- moved includes of vector/map/iostream/limits into ts.hpp
- require opencv_test + anonymous namespace (added compile check)
- fixed norm() usage (must be from cvtest::norm for checks) and other conflict functions
- added missing license headers