Binary package “libkf5style5” in ubuntu bionic

KF5 cross-framework integration plugins - KStyle

 Framework Integration is a set of plugins responsible
 for better integration of Qt applications when running
 on a KDE Plasma workspace.
 .
 libkf5style5 provides integration with KDE Plasma Workspace settings
 for Qt styles.
 .
 Derive your Qt style from KStyle to automatically inherit
 various settings from the KDE Plasma Workspace, providing a
 consistent user experience. For example, this will ensure a
 consistent single-click or double-click activation setting,
 and the use of standard themed icons.