CW-423 Use SensitiveClipboard for sensitive Stings (#1013)

* CW-423 Use SensitiveClipboard for sensitive Stings

* CW-423 Bump Android Target and Min SDK

* CW-423 Use Helper function for sensitive Clipboard

lib/utils/clipboard_util.dart

@@ -0,0 +1,15 @@
+import 'package:flutter/services.dart';
+
+import 'package:cake_wallet/utils/device_info.dart';
+import 'package:sensitive_clipboard/sensitive_clipboard.dart';
+
+class ClipboardUtil {
+  static Future<void> setSensitiveDataToClipboard(ClipboardData data) async {
+    if (DeviceInfo.instance.isMobile) {
+      await SensitiveClipboard.copy(data.text);
+      return;
+    }
+
+    return Clipboard.setData(data);
+  }
+}