Clean up imports in analysis_server and analyzer_cli (and one missed in analyzer)

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

Index: pkg/analysis_server/lib/src/search/type_hierarchy.dart
diff --git a/pkg/analysis_server/lib/src/search/type_hierarchy.dart b/pkg/analysis_server/lib/src/search/type_hierarchy.dart
index 0a666f32e3f9295ddead43502fc306b22fcc53f7..793e4717a30a553ff56ff83c8097218175bd488a 100644
--- a/pkg/analysis_server/lib/src/search/type_hierarchy.dart
+++ b/pkg/analysis_server/lib/src/search/type_hierarchy.dart
@@ -11,7 +11,8 @@ 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/src/generated/element.dart';
+import 'package:analyzer/dart/element/element.dart';
+import 'package:analyzer/dart/element/type.dart';
 
 /**
  * A computer for a type hierarchy of an [Element].