[kickoff] Wordwrap long sentence in config

Summary:
Text should always be constrained and should almost always elide or
wrap.

Note that the parent layout may be bigger than the view due to the
non-resizing nature of the Buttons UI so some different bugs still
exist.

BUG: 389124

Test Plan: Looked at it

Reviewers: #plasma, ngraham, hein

Reviewed By: #plasma, ngraham, hein

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D16419