Don't use ICustomHitTest

[timunie]

What does the pull request do?

Removes the usage of ICustomHitTest for our samples. This isn't needed. Instead, we should use Pointer*-events.

Scope of this PR:

• fix or update to an existing sample
• add a new sample

What is the current behavior?

Checklist

If this is a new Sample

• Added a ReadMe-file
• Updated the landing page
• Consider submitting a PR to https://github.com/AvaloniaUI/avalonia-docs with a link to your sample in the related documentation page

In any case

• Spell-checking done
• Checked if all hyperlinks work
• Checked if all images are visible

Fixed issues