core&ui: add compiler versions display

packages/ui-default/pages/problem_edit.page.styl

@@ -1,17 +1,4 @@
 .page--problem_edit,.page--problem_create
-  .section__tab-header-item
-    border-top: 3px solid transparent;
-    transition: border-color 0.2s, background 0.2s, color 0.2s;
-    transition-timing-function: cubic-bezier(0.215, 0.61, 0.355, 1);
-    margin-right: 0
-
-    &:hover
-      border-color: #5f9fd6;
-      background: #f8f8f8;
-    
-    &.tab--active
-      border-color: #ed5f82;
-
   .problem-sidebar-additional_file
     height: 270px
     overflow-y: auto