Add enhanced filters to Network panel.

Source/devtools/front_end/networkPanel.css

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Anthony Ricaud <rik@webkit.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 310 matching lines @@
     color: rgb(182, 0, 0);
 }
 
 .panel.network .split-view {
     flex: auto;
     position: relative;
 }
 
 .network-filters-header {
     flex: 0 0 23px;
+    padding-right: 4px;
 }