Make custom control label padding override easier

Created by: jacobmllr95

Currently it's quite difficult to override or remove the space between the custom control indicator and the actual label. You have to change the padding-left of the .custom-control and the negative left positioning of the indicator background and foreground.

With this PR you only have to change the padding-left of the .custom-control to the indicator size + x to control the space between indicator and label. The indicator will always remain all the way left relative to the .custom-control itself.