Show zero count in user counts

What does this MR do and why?

Adds ability to show zero count in user count component and turns it on for the user counts in the super sidebar/super topbar so that icons aren't just showing without a count which can lead to this weird alignment and not clearly indicating status (inbox zero).

Screenshots or screen recordings

Before	After
FF off

How to set up and validate locally

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Related to #548836 (closed)