Restructure the public API for server

pkg/analysis_server/lib/plugin/edit/assist/assist_dart.dart

Index: pkg/analysis_server/lib/plugin/edit/assist/assist_dart.dart
diff --git a/pkg/analysis_server/lib/edit/assist/assist_dart.dart b/pkg/analysis_server/lib/plugin/edit/assist/assist_dart.dart
similarity index 92%
rename from pkg/analysis_server/lib/edit/assist/assist_dart.dart
rename to pkg/analysis_server/lib/plugin/edit/assist/assist_dart.dart
index 742655cb50064a69de380b212943b12794bc37a3..737b3c4230546868e91b42148c1ab394486f1f92 100644
--- a/pkg/analysis_server/lib/edit/assist/assist_dart.dart
+++ b/pkg/analysis_server/lib/plugin/edit/assist/assist_dart.dart
@@ -2,9 +2,9 @@
 // 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.edit.assist.assist_dart;
+library analysis_server.plugin.edit.assist.assist_dart;
 
-import 'package:analysis_server/edit/assist/assist_core.dart';
+import 'package:analysis_server/plugin/edit/assist/assist_core.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';