Fix regression around FacePile with overflow (#11527)

* Work around compound-web AvatarStack not applying overlap to non-Avatars

* Fix FacePile overflow tile not being layed out correctly

Author: t3chguy

res/css/views/elements/_FacePile.pcss

@@ -20,6 +20,7 @@ limitations under the License.
     width: 30px;
     height: 30px;
     background-color: $spacePanel-bg-color;
+    display: inline-block;
 
     &::before {
         content: "";

src/components/views/elements/FacePile.tsx

@@ -57,7 +57,8 @@ const FacePile: FC<IProps> = ({
 
     const pileContents = (
         <>
-            {overflow ? <span className="mx_FacePile_more" /> : null}
+            {/* XXX: The margin-left is a workaround for Compound's styling excluding this element and being overly specific */}
+            {overflow ? <span className="mx_FacePile_more" style={{ marginLeft: `calc(${size} * -0.2)` }} /> : null}
             {faces}
         </>
     );