* add implicit convert operator for `Size->Size2f`

* more implicit conversion operators for size structs

* Update src/OpenCvSharp/Modules/core/Struct/Size.cs

* Update src/OpenCvSharp/Modules/core/Struct/Size.cs
Co-authored-by: Nshimat <schimatk@gmail.com>

* Update src/OpenCvSharp/Modules/core/Struct/Size2f.cs
Co-authored-by: Nshimat <schimatk@gmail.com>

---------
Co-authored-by: Nshimat <schimatk@gmail.com>

Co-authored-by: NIoannis Kaliakatsos <ioannis.kaliakatsos@reishauer.com>

* Update ubuntu20.yml

* Update ubuntu20.yml

* Update ubuntu20.yml

* Update ubuntu20.yml

* Update ubuntu20.yml

* Update ubuntu20.yml

* Update ubuntu20.yml

* Update ubuntu20.yml

* Update ubuntu20.yml

* Wrap reduceArgMin and reduceArgMax

(cherry picked from commit 01f9e24339e4f20665934526bc6285e43106af8a)

* Mark boolean P/Invoke argument with MarshalAs and adapt unit tests

* Fix unit test assertions

* 460 -> 470

* ErrorActionPreference

* update samples

* rename ubuntu20 id

* rename

* ubuntu22-dotnet6sdk-opencv4.7.0

* remove libavresample

* 4.7.0

* 22

* artifacts

* update to 4.7

Add MatMemoryManager and Mat.AsSpan

Fix null pointer error

Fix null pointer error

Error messages：
Unhandled exception. System.TypeInitializationException: The type initializer for 'OpenCvSharp.Internal.NativeMethods' threw an exception.
 ---> System.DllNotFoundException: Unable to load shared library 'OpenCvSharpExtern' or one of its dependencies. In order to help diagnose loading problems, consider setting the LD_DEBUG environment variable: libOpenCvSharpExtern: cannot open shared object file: No such file or directory
   at OpenCvSharp.Internal.NativeMethods.redirectError(CvErrorCallback errCallback, IntPtr userdata, IntPtr& prevUserdata)
   at OpenCvSharp.Internal.ExceptionHandler.RegisterExceptionCallback()
   at OpenCvSharp.Internal.NativeMethods.LoadLibraries(IEnumerable`1 additionalPaths)
   at OpenCvSharp.Internal.NativeMethods..cctor()
   --- End of inner exception stack trace ---
   at OpenCvSharp.Internal.NativeMethods.videoio_VideoCapture_delete(IntPtr obj)
   at OpenCvSharp.VideoCapture.DisposeUnmanaged()
   at OpenCvSharp.DisposableObject.Dispose(Boolean disposing)
   at OpenCvSharp.DisposableObject.Finalize()

setup-dotnet@v2

Update CMakeLists.txt

Restore LineSegmentDetector

iconv support isn't automatic on some systems

file-scoped namespaces