basic csv loader, transaction list & half done stats page

lib/clients/storage/storage_client.dart

@@ -0,0 +1,24 @@
+import 'dart:io';
+
+import 'package:path_provider/path_provider.dart';
+
+class StorageClient {
+    save(String filename, String data) async {
+        File file = await _getJson(filename);
+        await file.writeAsString(data);
+    }
+
+    Future<String> load(String filename) async {
+        File file = await _getJson(filename);
+        return file.readAsString();
+    }
+
+    Future<File> _getJson(String filename) async {
+        final dir = await getApplicationDocumentsDirectory();
+        final file = File('${dir.path}/$filename'); 
+        if (!file.existsSync()) {
+          file.createSync();
+        }
+        return file;
+    }
+}