Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

• I agree to contribute to the project under Apache 2 License.
• To the best of my knowledge, the proposed patch is not based on a code under GPL or other license that is incompatible with OpenCV
• The PR is proposed to proper branch
• There is reference to original bug report and related work
• There is a test

A function like "at" for Java/Kotlin (partner to #20220 )
Includes some Kotlin extensions (Android only) to allow you do cool things like:

val (b, g, r) = lena.at<UByte>(10, 10).v3c

Also includes ability to disable Kotlin extensions for anyone that doesn't want them

allow_multiple_commits=1