Move ResolverProvider to analyzer so that it can be shared

pkg/analysis_server/lib/plugin/analysis/resolver_provider.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 analysis_server.plugin.analysis.resolver_provider;
-
-import 'package:analyzer/file_system/file_system.dart';
-import 'package:analyzer/src/generated/source.dart';
-
-/**
- * A function that will return a [UriResolver] that can be used to resolve a
- * specific kind of URI within the analysis context rooted at the given folder.
- * This is currently being used to provide a package URI resolver that will be
- * used by the server (see [ServerStarter.packageResolverProvider]).
- */
-typedef UriResolver ResolverProvider(Folder folder);