Start integrating Rust extension

Author: simolus3

packages/powersync_core/lib/src/sync/mutable_sync_status.dart

@@ -1,8 +1,8 @@
 import 'dart:async';
 
 import 'package:collection/collection.dart';
+import 'package:powersync_core/src/sync/instruction.dart';
 
-import 'instruction.dart';
 import 'sync_status.dart';
 import 'bucket_storage.dart';
 import 'protocol.dart';

packages/powersync_core/lib/src/sync/streaming_sync.dart

@@ -248,6 +248,7 @@ class StreamingSyncImplementation implements StreamingSync {
       }
 
       assert(identical(_activeCrudUpload, completer));
+      _nonLineSyncEvents.add(const UploadCompleted());
       _activeCrudUpload = null;
       completer.complete();
     });