* [hal][neon] Optimize the v_dotprod_fast intrinsics for aarch64.

On Armv8 in AArch64 execution mode, we can skip the sequence

   v<op>_<ty>(vget_high_<ty>(x), vget_high_<ty>(y))

in favour of

   v<op>_high_<ty>(x, y)

This has better changes for recent compilers to use less data movement
operations and better register allocation. See for example:

   https://godbolt.org/z/bPq7vd

* [hal][neon] Fix build failure on armv7.

* [hal][neon] Address review comments in PR.

PR: https://github.com/opencv/opencv/pull/19486

* [hal][neon] Define macro to check for the AArch64 execution state of Armv8.

* [hal][neon] Fix macro definition for AArch64.

The fix is needed to prevent warnings when building for Armv7.

Exif parsing for PNG files to support Exif orientation tag.  Moved decoder specific Exif parsing to JPEG and PNG decoders, respectively. Issue 16579

This fixes #19463

QRCodeDetector::decodeMulti() fixed invalid usage fixedType()

* fixed invalid usage fixedType()
changed default barcode type to CV_8UC1
added tests
added assert in case multi channel straight barcode input

* deleted extra wrap into OutputArray

* fix warnings

* objdetect(qr): remove unnecessary checks
Co-authored-by: NAlexander Alekhin <alexander.a.alekhin@gmail.com>

* add LeakyRelu to tf-importer

* fix whitespace error

* added test for leakyrelu

they might be thrown from third-party code (notably Ogre in the ovis
module).
While Linux is kind enough to print them, they cause instant termination
on Windows.
Arguably, they do not origin from OpenCV itself, but still this helps
understanding what went wrong when calling an OpenCV function.

* Fix error in documentation for RGB->HSV convertion

* Update colors.markdown

Instead of being a copy of line 76, line 79 instead correctly indicates that it will show a histogram for a gray image in curve mode, as given by the code block at line 103 referencing image "gray" instead of image "im".

* fix opencv/opencv#19402

* Fixed bug with constant Div

* Supported constant mul and div for inputs with different shapes