add hover style to userlist user and chat items

bigbluebutton-html5/imports/ui/components/user-list/chat-list-item/styles.scss

@@ -14,6 +14,10 @@
     box-shadow: inset 0 0 0 $border-size $item-focus-border, inset 1px 0 0 1px $item-focus-border;
     outline: none;
   }
+
+  &:hover {
+    background-color: $list-item-bg-hover;
+  }
 }
 
 .chatListItemLink {

bigbluebutton-html5/imports/ui/components/user-list/user-list-content/user-participants/user-list-item/user-list-content/styles.scss

@@ -87,6 +87,10 @@
     box-shadow: inset 0 0 0 $border-size $item-focus-border, inset 1px 0 0 1px $item-focus-border;
     outline: none;
   }
+
+  &:hover {
+    background-color: $list-item-bg-hover;
+  }
 }
 
 .userAvatar {