Add support for pivot tables.

Currently, RadSpreadProcessing supports the following options:

namespace Telerik.Windows.Documents.Model.Drawing.Charts
{
    /// <summary>
    /// Specifies where a chart legend is placed relative to the plot area.
    /// </summary>
    public enum LegendPosition
    {
        /// <summary>
        /// Positions the legend to the right of the plot area.
        /// </summary>
        Right,

        /// <summary>
        /// Positions the legend below the plot area.
        /// </summary>
        Bottom,

        /// <summary>
        /// Positions the legend to the left of the plot area.
        /// </summary>
        Left,

        /// <summary>
        /// Positions the legend above the plot area.
        /// </summary>
        Top
    }
}

MS Excel supports setting "Top Right" Legend Position:

Currently, if you have a decimal column in the DataTable, it is imported as a text column in the workbook. It should be preserved as a numeric column after importing.

Note: When importing a DataTable, each of the column's type is checked and a respective cell type is imported. 

 if (dataType.IsValueType && dataType.IsPrimitive && !dataType.IsEnum)
                    {
                        newValue = new NumberCellValue(Convert.ToDouble(value));
                    }

You need to explicitly set the correct MIME type when embedding the file into the PDF. This is especially important for standards like PDF/A-3 and Factur-X, which require strict metadata and MIME type declarations for embedded files.

The default value /application/octet-stream is too generic and not compliant for XML attachments.

Hello support team,

We faced an exception that ShadingType 1 is not supported. Can you please confirm that this is expected?

Regards,
Vitalii

Some PDF files have an additional content added before the file header (before %PDF-1.4 for example). This additional content makes all byte offsets in the document invalid, which causes the format provider to throw an exception.

At this point, to import a similar document it should be pre-processed so the content before the version header is removed before importing it.

When importing a large document (e.g. 2.3GB) , the library fails to parse int value that exceeds the limit which leads to endless importing: