Screen backlight change notification should appear on the affected screen

## Prerequisites
- [x] I have searched open and closed issues for duplicates.

## Feature
**Is your feature request related to a problem? Please describe.**
I have a laptop with an external monitor and when I work the external monitor is my primary output. When I press the "decrease/increase backlight level" key on the keyboard, I see the light increasing on my laptop but the notification is on my external monitor which remains unaffected.

**Describe the solution you'd like**
Show the backlight level notification on the screen that is actually changing its level

**Existing work**
N/A

**Describe alternatives you've considered**
N/A

**Additional context**
N/A