Add "preferences-desktop-navigation" icon

Summary:
BUG: 402910

Test Plan: Search for "preferences-desktop-navigation" in Cuttlefish.

Reviewers: VDG, ndavis

Reviewed By: VDG, ndavis

Subscribers: kde-frameworks-devel, VDG

Tags: Frameworks

Differential Revision: https://phabricator.kde.org/D23749