Add flamegraph to list of dynamic search links (#471)

This adds flamegraph to the list of dynamic search links so that query parameters are retained when navigating to/from the flamegraph view.

internal/driver/webhtml.go

     toptable.addEventListener('touchstart', handleTopClick);
   }
 
-  const ids = ['topbtn', 'graphbtn', 'peek', 'list', 'disasm',
+  const ids = ['topbtn', 'graphbtn', 'flamegraph', 'peek', 'list', 'disasm',
                'focus', 'ignore', 'hide', 'show', 'show-from'];
   ids.forEach(makeSearchLinkDynamic);