Move plasma-manager import to plasma config file, no need to import if
not using plasma desktop
Add libnotify to default installed packages for desktop environment
Split system-level sway and plasma config into separate files, move
sway-specific home-level config to sway file. Only truly common
desktop components are kept in common spaces. This allows much easier
switching between using KDE Plasma and Sway.
Evie Litherland-Smith