Make isLastItem inset optional

[readeral]

Hi there,

It would be great if the following condition was optional:

if(this.isLastItem)
        {
            classList.push('comm-drilldown-navigation__list-last');
        }

maybe with an @api ignoreLastItemInset

if(this.isLastItem && !this.ignoreLastItemInset)
        {
            classList.push('comm-drilldown-navigation__list-last');
        }

This is especially felt on small menus where the menu is aligned left, there is never a chance the right-most menu item will be at the edge of the window.

Happy to make a PR if acceptable