add chunk feature

[steamboatid]

Hello,
this is my first PR.

Inspired by some discussion around github especially PR #3605 and issu #4121 also phpunit-slicer
I'm not using branch master, instead branch 9.5 because master branch seem for version 10. I did diff the branches and the different is huge. Tons of new file in the master branch. I already follow all the suggested steps in Contributing Guidline, even create some development scripts in the directory build/scripts.
I simply using local LXC and mimic all ci.yml content into my box.

Developed using PHP 8.0 and Debian 11 Bullseye.
As always, please ignore any changes, that you may think not important.

Many thanks in advance.

[sebastianbergmann]

Thank you for your contribution. I appreciate the time you invested in preparing this pull request. However, new features must go into the master branch. PHPUnit 9.5 will not get any new features.

[steamboatid]

Thank you for your contribution. I appreciate the time you invested in preparing this pull request. However, new features must go into the master branch. PHPUnit 9.5 will not get any new features.

hi @sebastianbergmann ,
OK. the code is there, so you may consider as new addition to next version or maybe future version