Add Kotlin (.kt) mimetype icons
Summary:
FEATURE: 401299
FIXED-IN: 5.54
Add an icon for Kotlin files (.kt).
Test Plan:
Reviewers: VDG, ngraham, ndavis
Reviewed By: VDG, ngraham, ndavis
Subscribers: alex-l, ngraham, kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D18199