Widget Visibility: Page Visibility on Non-Legacy Widgets Doesn't Allow Including Children

### Impacted plugin

Jetpack

### Steps to Reproduce

1. Turn on Jetpack's Widget Visibility
2. Add a legacy widget to a widget area (for example, meta)
3. You can select to show/hide a widget if a page and its children match via a checkbox
4. Add a non-legacy widget and select visibility
5. There is no option to select children pages

### A clear and concise description of what you expected to happen.

Visibility on non-legacy widgets should have the same option

### What actually happened

The non-legacy widget doesn't have the "Include Children" option

### Other information

Screenshot of legacy widget visibility:

Screenshot of non-legacy widget visibility:

Originally reported here:
https://wordpress.org/support/topic/jetpack-widget-visibility-setting/?view=all

### Operating System

macOS

### OS Version

12.1

### Browser

Firefox

### Browser Version(s)

Latest

Reproduce the difference between legacy and non-legacy widgets in Jetpack's Widget Visibility settings, using the steps and screenshots in the issue as the starting point. Compare both visibility controls and confirm that non-legacy widgets expose the same “Include Children” option and apply it correctly.

Written by the indexing model from the issue text.