[MVC] Counter dark mode hover/focus styles

The <counter> component in the super sidebar does not have styles for :hover/:focus/:active states in dark mode.

Default Hover
127.0.0.1_3000_search 127.0.0.1_3000_search__1_

Figma: https://www.figma.com/file/kAAMkIqKPE4rRYo1JQIheI/Navigation-Redesign?node-id=1945%3A143645&t=coKLpAca8nhFPXAp-4

Edited by Scott de Jonge