Change avatar to use Compound implementation (#11448)

* Move avatar to new compound implementation

* Make space avatars square

* Remove reference to the avatar initial CSS class

* remove references to mx_BaseAvatar_image

* Fixe test suites

* Fix accessbility violations

* Add ConfirmUserActionDialog test

* Fix tests

* Add FacePile test

* Fix items clipping in members list

* Fix user info avatar sizing

* Fix tests

src/components/views/rooms/ThreadSummary.tsx

@@ -101,8 +101,7 @@ export const ThreadMessagePreview: React.FC<IPreviewProps> = ({ thread, showDisp
             <MemberAvatar
                 member={lastReply.sender}
                 fallbackUserId={lastReply.getSender()}
-                width={24}
-                height={24}
+                size="24px"
                 className="mx_ThreadSummary_avatar"
             />
             {showDisplayname && (