* Add TotalsWrapper component and associated styling
* Add TotalsWrapper around the subtotal, fees and discount
* Remove margins/paddings/borders from sidebar elements
This is to allow TotalsWrapper to be the component responsible for handling spacing and borders.
* Update styles to allow components to be wrapped in TotalsWrapper
* Move TotalsWrapper to checkout package
* Wrap all parts of Cart sidebar in TotalsWrapper
* Remove border from coupon panel
* Add has-bottom-border option to TotalsWrapper
* Wrap checkout sidebar components in TotalsWrapper
* Remove border/padding from order summary
* Add hasValidFills function
This will be used to check if a Slot has any fills that return truthy values.
* Remove borderSize and hasBottomBorder props from TotalsWrapper
* Wrap Slots in TotalsWrapper
* Update hasValidFills to check length of array
* Update tests and snapshots
* Only render tax totals if tax is more than 0