Renaming "legacy" paths and DDC modules to "DDC" paths and modules. (#2360)

Renaming "legacy" paths and DDC modules to "DDC" paths and modules.

This aligns our naming scheme for the DDC module system.

Author: Markzipan

dwds/CHANGELOG.md

@@ -1,6 +1,7 @@
 ## 23.4.0-wip
 
 - Adding tests for constants in DDC after a hot restart - [#2349](https://github.com/dart-lang/webdev/pull/2349)
+- Renaming `dart_library.js` to `ddc_module_loader.js` to match SDK naming changes - [#2360](https://github.com/dart-lang/webdev/pull/2360)
 
 ## 23.3.0
 

dwds/lib/dwds.dart

@@ -19,11 +19,11 @@ export 'src/handlers/dev_handler.dart' show AppConnectionException;
 export 'src/handlers/socket_connections.dart';
 export 'src/loaders/build_runner_require.dart'
     show BuildRunnerRequireStrategyProvider;
-export 'src/loaders/frontend_server_legacy.dart'
-    show FrontendServerLegacyStrategyProvider;
+export 'src/loaders/ddc.dart' show DdcStrategy;
+export 'src/loaders/frontend_server_ddc.dart'
+    show FrontendServerDdcStrategyProvider;
 export 'src/loaders/frontend_server_require.dart'
     show FrontendServerRequireStrategyProvider;
-export 'src/loaders/legacy.dart' show LegacyStrategy;
 export 'src/loaders/require.dart' show RequireStrategy;
 export 'src/loaders/strategy.dart'
     show LoadStrategy, ReloadConfiguration, BuildSettings;