Default KDE/Plasma install cleanups and improvements

• Drop kde-standard dependencies already pulled transitively:
  • polkit-kde-agent, plasma-nm pulled by plasma-desktop
  • plasma-dataengines-addons already pulled by plasma-widgets-addons
• Drop kde-plasma-desktop dependencies already pulled transitively:
  • plasma-workspace pulled by plasma-desktop
• Add packages to kde-plasma-desktop Recommends as per upstream packaging recommendations:
  • bump kdeconnect from Suggests to Recommends
  • iio-sensor-proxy: allows automatic screen rotation on Wayland
  • maliit-keyboard: provides on-screen keyboard on Wayland
  • power-profiles-daemon: enables the power profile functionality in Plasma