Set a component display name for the action collection of ksmserver

Summary: "ksmserver" is not a good user visible string.

Test Plan: check in global shortcuts kcm

Reviewers: ngraham, #plasma, #vdg, davidedmundson

Reviewed By: ngraham, #plasma, #vdg, davidedmundson

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D29058