ngraham recommended that I split up https://phabricator.kde.org/D27438 into three patches:
1. The foundation code to get landed first so that the other two patches can be done as patches that change two separate lines instead of just one
2. Tablet Mode increases tray icon spacing
3. Increase tray icon spacing slightly on Non-Tablet Mode (half of the amount it increases by in Tablet Mode)
This patch integrates both patch 1 and 2 of what ngraham recommended to make system tray icon click areas larger when Kirigami's Tablet Mode setting is true than they normally are.