make copy work, also some abstraction and new provider

lib/providers/sftp_loading_provider.dart

@@ -0,0 +1,40 @@
+import 'package:flutter/material.dart';
+
+class SftpLoadingProvider extends ChangeNotifier {
+
+  double? _uploadProgress;
+  double? _downloadProgress;
+  
+  double? _copyProgress;
+  List<String>? _toBeMovedOrCopied;
+  bool _isCopy = false;
+
+
+  double? get copyProgress => _copyProgress;
+  double? get uploadProgress => _uploadProgress;
+  double? get downloadProgress => _downloadProgress;
+
+  List<String>? get toBeMovedOrCopied => _toBeMovedOrCopied;
+  bool get isCopy => _isCopy;
+
+  void setUploadProgress(double? progress) {
+    _uploadProgress = progress;
+    notifyListeners();
+  }
+
+  void setDownloadProgress(double? progress) {
+    _downloadProgress = progress;
+    notifyListeners();
+  }
+
+  void setCopyProgress(double? progress) {
+    _copyProgress = progress;
+    notifyListeners();
+  }
+
+  void setCopyOrMoveFiles(List<String>? files, bool isCopy) {
+    _toBeMovedOrCopied = files;
+    _isCopy = isCopy;
+    notifyListeners();
+  }
+}