Bring back the list titles in desktop mode, style .pushgroup action on contacts list

There's one reason we want list titles also in desktop mode. In Addressbook
when using filter_groups feature the title provides an option to navigate
to previous level of the list.

skins/elastic/styles/layout.less

@@ -221,10 +221,6 @@ html.iframe body {
     body > #layout > div > .header > a.back-sidebar-button {
         display: none;
     }
-
-    body > #layout > .list > .header > .header-title {
-        display: none;
-    }
 }
 
 @media screen and (min-width: (@screen-width-small + 1px)) {

skins/elastic/styles/widgets/lists.less

@@ -65,7 +65,6 @@
     }
 
     td.action {
-        // TODO
         padding: 0 .5em;
         width: 2em;
         text-align: center;
@@ -73,6 +72,22 @@
         &:empty {
             width: 0;
         }
+
+        a {
+            display: block;
+            overflow: hidden;
+            text-decoration: none;
+
+            &:before {
+                &:extend(.font-icon-class);
+                margin: 0;
+                font-size: 1rem;
+            }
+        }
+
+        a.pushgroup:before {
+            content: @fa-var-chevron-right;
+        }
     }
 
     li.droptarget > a,