Bug: Composite health contributors' details are not shown

Hello.

I discovered this bug while working on https://github.com/codecentric/spring-boot-admin/issues/5525 and, while we don't use (so far) composite health contributors and therefore it's not an issue for us, I decided to report this to improve the product.

Bug: If some health contributors are of type CompositeHealthContributor, the UI shows the contained contributors as separate health contributors (arguable, but out of scope here) but the details that they carry are not rendered and only their status is shown.

An example can be seen in the screenshot attached in https://github.com/codecentric/spring-boot-admin/pull/5526.
The discoveryComposite is a composite health contributor which contains the discoveryClient contributor.
For both, no details are shown even if the JSON returned by the /actuator/health call indicates there are 3 available items (the discoveryClient contributor itself plus 2 additional details).

Compare the UI rendering with the JSON returned by the /actuator/health endpoint, focusing on CompositeHealthContributor and the discoveryComposite/discoveryClient example described in the issue. Done means the details for composite contributors are rendered in the UI rather than only their statuses.