fix: bring node labels to top layer on hover

[karthikjeeyar]

Fixes

https://github.com/patternfly/react-topology/issues/127

Description

Bring the node/group label to front when the node/group is hovered.

Type of change

• [x] Bugfix

Screen shots / Gifs for design review

Before:

After:

[github-actions[bot]]

:tada: This PR is included in version 5.2.0-prerelease.4 :tada:

The release is available on:

• GitHub release
• npm package (@prerelease dist-tag)

Your semantic-release bot :package::rocket: