Normalize avatar radius (#11589)

We already made avatars square for .ui avatar.img class but this is not enough, and in some place Fomantic default styling still applied.

This PR updates our override of radius to match all Fomantic classes.

web_src/less/_base.less

         font-weight: normal;
     }
 
-    .avatar.image {
+    .avatar.image,
+    .avatar.image img,
+    .avatar.image svg,
+    .avatar.images .image,
+    .avatar.images img,
+    .avatar.images svg {
         border-radius: 3px;
     }