Fix avatars displaying as block elements

What does this MR do and why?

This MR fixes avatars displaying as block elements, which was accidentally caused by !90925 (merged).

With !90925 (merged), avatars started displaying as block elements after they were updated with display: flow-root. This created a BFC which we wanted in order to contain the floated avatars to fix the avatar focus rings. However, this makes the element a block. We can make the element inline instead with a BFC with display: inline-block.

Changelog: fixed

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