Remove more libraries directives from server

pkg/analysis_server/lib/src/search/type_hierarchy.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-library analysis.type_hierarhy;
-
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analysis_server/src/protocol_server.dart'
     show TypeHierarchyItem, convertElement;
 import 'package:analysis_server/src/services/search/hierarchy.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 
@@ skipping 178 matching lines @@
         return null;
       }
       if (result != null) {
         return result;
       }
     }
     // not found
     return null;
   }
 }