Add padding options for dashboard, power menu, notification center popups

[Chamal1120]

Problem: At the time this writing there is no option to move the popups like dashboard or notification center away from the edge of the screen which makes it is not good looking when using with the floating bar option as it leaves gap from left and right side of the bar.

Preferred solution: Provide an option to adjust the padding or distance from the edges so we can position them the according to our liking.

Please look at the screenshots below to get an idea.