fixed the ordering of contour convex hull points

* partially fixed the issue #4539

* fixed warnings and test failures

* fixed integer overflow (issue #14521)

* added comment to force buildbot to re-run

* extended the test for the issue 4539. Check the expected behaviour on the original contour as well

* added comment; fixed typo, renamed another variable for a little better clarity

* added yet another part to the test for issue #4539, where we run convexHull and convexityDetects on the original contour, without any manipulations. the rest of the test stays the same

* fixed several problems when running tests on Mac:
* OCL_pyrUp
* OCL_flip
* some basic UMat tests
* histogram badarg test (out of range access)

* retained the storepix fix in ocl_flip only for 16U/16S datatype, where the OpenCL compiler on Mac generates incorrect code

* moved deletion of ACCESS_FAST flag to non-SVM branch (where SVM is shared virtual memory (in OpenCL 2.x), not support vector machine)

* force OpenCL to use read/write for GPU<=>CPU memory transfers on machines with discrete video only on Macs. On Windows/Linux the drivers are seemingly smart enough to implement map/unmap properly (and maybe more efficiently than explicit read/write)

Adding python codes to samples/python

* Python version of samples:
- laplace.py
- drawing.py

* Update drawing.py

* Update drawing.py

* Update drawing.py

* Update laplace.py

* Update laplace.py

* Update drawing.py

* Update drawing.py

* Update laplace.py

* samples

* drawing

* drawing

* drawing.py

use const instead of constexpr

* dnn(test): test DLDT IRv10 model, drop old models

* dnn(test): don't expect bitexact results in DLDT IR tests

Add CP-VTON sample

* Support resize from PyTorch

* Add CP-VTON sample

* Fix downsampling

* Fix test

* Add model links

* Add default args

* Speed up resize

* Fix TOM link

* Add default args

* Fix comments

* Set aspect ratio for input

* Update links

* Check files exist

fixed cv::moveWindow() on mac

* fixed cv::moveWindow() on mac (issue #16343). Thanks to cwreynolds and saskatchewancatch for the help!

* fixed warnings about _x0 and _y0

* fixed warnings about _x0 and _y0

* Fix NN resize with dimentions > 4

* add test check for nn resize with channels > 4

* Change types from float to double

* Del unnecessary test file. Move nn test to test_imgwarp. Add 5 channels test only.

* fixed typo

* add compatibility code to handle migration

* fixed Split layer in ONNXImporter

* added test for fix of split layer

* fixed tests for Split layer

* applied reviews

* updated tests

* fixed paths in tests