function toPadding(value) {
    const obj = toTRBL(value);
    obj.width = obj.left + obj.right;
    obj.height = obj.top + obj.bottom;
    return obj;
}
Converts the given value into a padding object with pre-computed width/height.
@param value - If a number, set the value to all TRBL component,
 else, if an object, use defined properties and sets undefined ones to 0.
 x / y are shorthands for same value for left/right and top/bottom.
@returns The padding values (top, right, bottom, left, width, height)
@since 2.7.0