Add helper for adding data to an exception while throwing it

[AArnott]

The actual code is below, which could be used as follows.

            throw new ArgumentException("Overlapping spans").AddData(bufferSpans.Key, bufferSpans.Value[s], bufferSpans.Value[s - 1]);
// or
            throw new ArgumentException("Overlapping spans").Modify((e) => e.Data.Add("bufferSpans", bufferSpans));

    public static class ExceptionsWithData
    {
        /// <summary>
        /// Add <paramref name="data"/> to the Data member of <paramref name="e"/> before returning the modified exception.
        /// </summary>
        /// <remarks>
        /// <para>This method should be used to add context (beyond the message and callstack we normally get) to the exception
        /// that would be useful when debugging Watson crashes.</para>
        /// <para>Do not use this method when you expect the exception to be handled.</para>
        /// </remarks>
        public static T AddData<T>(this T e, params object[] data) where T : Exception
        {
            if (data.Length > 0)
            {
                e.Data.Add("AddData", data);
            }
 
            return e;
        }
 
        /// <summary>
        /// Modify <paramref name="e"/> by performing <paramref name="action"/> on it before returning the modified exception.
        /// </summary>
        /// <remarks>
        /// <para>This method should be used to add context (beyond the message and callstack we normally get) to the exception
        /// that would be useful when debugging Watson crashes.</para>
        /// <para>Do not use this method when you expect the exception to be handled.</para>
        /// </remarks>
        public static T Modify<T>(this T e, Action<T> action) where T : Exception
        {
            if (action != null)
            {
                action(e);
            }
 
            return e;
        }
    }