[Feature] Keyboard backlight mode settings

[iceking-1912]

What would you like to be added?
There Should be a slider for Keyboard Backlight brightness level
& Keyboard backlight Led Mode selecter
and a Gnome like section for Power control (Performance/Balanced/Quiet)

How will it help
in my case i have asus laptop so in linux Asusctl cli helps to change diffrent mode so we can do it with asusctl cli integration

For Led Mode

asusctl led-mode static 
asusctl led-mode rainbow-wave

For Led Brightness level

asusctl  --kbd-bright high
asusctl  --kbd-bright off

likewise-

For Power Control Profile

asusctl  profile -n #for next profile
asusctl  profile --profile-set quiet #to set a particular profile

Extra info
Similar to Brightness/Volume slider
and a Section for Led-mode and Power Control like we have for Bluetooth/Wifi