Pictures covered the border

[YancyHsu]

flutter-widgets/packages/syncfusion_flutter_xlsio/lib/src/xlsio/general/serialize_workbook.dart

Line 1843 in aa1c111

builder.element('xdr:colOff', nest: 0);

Suggest nest to be 10000, so picture will not cover the border.

Or class Picture add rowOffset and colOffset to have more flexible settings.