Adjust date string height to match time string with vertical panel

Summary:
Changes the height of the date string to match that of the
time string so the date is readable with a vertical panel

BUG: 404611

Reviewers: #vdg, #plasma, davidedmundson, Zren, ngraham, rooty

Reviewed By: #vdg, ngraham, rooty

Subscribers: rooty, cfeck, mart, ngraham, davidedmundson, Zren, abetts, anthonyfieroni, plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D19194