Data list - update expandable data list demo to match core

[nicolethoen]

trafficstars

Follow up to https://github.com/patternfly/patternfly/issues/4767

Replace the existing expandable data list demo with a full page demo to match the one in core.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.

[adamviktora]

Can I get this issue assigned?

Or is this issue already solved? (as mentioned in https://github.com/patternfly/patternfly-react/issues/7227)

If I understand correctly, we want to replace the current React demo (https://www.patternfly.org/v4/components/data-list/react-demos#expandable-control-in-toolbar) with a new one, that is a full page demo, that looks like this HTML demo: https://www.patternfly.org/v4/components/data-list/html-demos/expandable-demo/

[tlabaj]

The demo already exists