- eliminate CMake 3.5+ warnings
- removed usage of dropped "OPENCV_CAMERA_MODULES" variable
- partial support for Android NDK 11+

Updated integrations for:
cv::split
cv::merge
cv::insertChannel
cv::extractChannel
cv::Mat::convertTo - now with scaled conversions support
cv::LUT - disabled due to performance issues
Mat::copyTo
Mat::setTo
cv::flip
cv::copyMakeBorder - currently disabled
cv::polarToCart
cv::pow - ipp pow function was removed due to performance issues
cv::hal::magnitude32f/64f - disabled for <= SSE42, poor performance
cv::countNonZero
cv::minMaxIdx
cv::norm
cv::canny - new integration. Disabled for threaded;
cv::cornerHarris
cv::boxFilter
cv::bilateralFilter
cv::integral

Updated comments for cv::ellipse and cv::ellipse2Poly to clarify some behaviour that has confused some users.

Amend: Delete trailing whitespace to make doc tests happy

Add support for std::array<T, N> (#8535)

* Add support for std::array<T, N>

* Add std::array<Mat, N> support

* Remove UMat constructor with std::array parameter

Gemm kernels for Intel GPU (#8104)

* Fix an issue with Kernel object reset release when consecutive Kernel::run calls

Kernel::run launch OCL gpu kernels and set a event callback function
to decreate the ref count of UMat or remove UMat when the lauched workloads
are completed. However, for some OCL kernels requires multiple call of
Kernel::run function with some kernel parameter changes (e.g., input
and output buffer offset) to get the final computation result.
In the case, the current implementation requires unnecessary
synchronization and cleanupMat.

This fix requires the user to specify whether there will be more work or not.
If there is no remaining computation, the Kernel::run will reset the
kernel object
Signed-off-by: Woo, Insoo <insoo.woo@intel.com>

* GEMM kernel optimization for Intel GEN

The optimized kernels uses cl_intel_subgroups extension for better
performance.

Note: This optimized kernels will be part of ISAAC in a code generation
way under MIT license.
Signed-off-by: Woo, Insoo <insoo.woo@intel.com>

* Fix API compatibility error

This patch fixes a OCV API compatibility error. The error was reported
due to the interface changes of Kernel::run. To resolve the issue,
An overloaded function of Kernel::run is added. It take a flag indicating
whether there are more work to be done with the kernel object without
releasing resources related to it.
Signed-off-by: Woo, Insoo <insoo.woo@intel.com>

* Renaming intel_gpu_gemm.cpp to intel_gpu_gemm.inl.hpp
Signed-off-by: Woo, Insoo <insoo.woo@intel.com>

* Revert "Fix API compatibility error"

This reverts commit 2ef427db91b6c4aec170f691c5d2e6c47d6520d7.

Conflicts:
	modules/core/src/intel_gpu_gemm.inl.hpp

* Revert "Fix an issue with Kernel object reset release when consecutive Kernel::run calls"

This reverts commit cc7f9f54695dc293598addce9b9d7e345225bede.

* Fix the case of uninitialization D

When C is null and beta is non-zero, D is used without initialization.
This resloves the issue
Signed-off-by: Woo, Insoo <insoo.woo@intel.com>

* fix potential output error due to 0 * nan
Signed-off-by: Woo, Insoo <insoo.woo@intel.com>

* whitespace fix, eliminate non-ASCII symbols

* fix build warning

repair broken cmdline param for cpu/gpu mode