Move SdkExtUriResolver from analysis_server to analyzer so it can be used in analyzer_cli

pkg/analysis_server/test/src/test_all.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 test.src;
 
 import 'package:unittest/unittest.dart';
 
-import 'sdk_ext_test.dart' as sdk_ext_test;
 import 'utilities/test_all.dart' as utilities_all;
 
 /**
  * Utility for manually running all tests.
  */
 main() {
   groupSep = ' | ';
   group('analysis_server', () {
-    sdk_ext_test.main();
     utilities_all.main();
   });
 }