Clean up package imports and library names

pkg/analyzer/test/source/sdk_ext_test.dart

 // Copyright (c) 2015, 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 test.source.sdk_ext;
+library analyzer.test.source.sdk_ext_test;
 
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/source/sdk_ext.dart';
 import 'package:unittest/unittest.dart';
 
 import '../utils.dart';
 
 main() {
   initializeTestEnvironment();
   group('SdkExtUriResolverTest', () {
@@ skipping 61 matching lines @@
     "dart:bear": "grizzly.dart",
     "dart:relative": "../relative.dart",
     "dart:deep": "deep/directory/file.dart",
     "fart:loudly": "nomatter.dart"
   }''');
 }
 
 clearResourceProvider() {
   resourceProvider = null;
 }