Kicker/Documents optimization: Lazily build KFileItem
Summary:
Save quite a few KFileItem instanciation.
On each document hovering several KFileItem were instanciated for nothing.
Reviewers: Frameworks, apol
Reviewed By: apol
Subscribers: apol, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D26416