TSV - Exception on blank field value

[jamesflagg]

Unit test to reproduce the problem:
`

public class ChoTests
{
    [Fact]
    public void CanReadTabDelimitedWithBlankFieldValue()
    {
        using (var reader = ChoTSVReader.LoadText("A\t\tB").ErrorMode(ChoErrorMode.ThrowAndStop))
        {
            foreach(var record in reader)
            {
                Assert.NotNull(record);
                Assert.Equal("A", record.Column1);
                Assert.Null(record.Column2);
                Assert.Equal("B", record.Column3);
            }
        }
    }
}

`

This throws an exception, when it should gracefully populate the record.
It is apparently a side effect of the delimiter (tab) being considered whitespace.
Stack trace:
`

at ChoETL.ChoUtility.RightOf(String source, String searchText)
at ChoETL.ChoCSVRecordReader.GetFieldValues(String line)
at ChoETL.ChoCSVRecordReader.FillRecord(Object rec, Tuple2 pair)
at ChoETL.ChoCSVRecordReader.LoadLine(Tuple2 pair, Object& rec)
at ChoETL.ChoCSVRecordReader.AsEnumerable(Object source, TraceSwitch traceSwitch, Func2 filterFunc)+MoveNext()
at ChoETL.ChoEnumeratorWrapper.BuildEnumerable[T](Func1 moveNext, Func1 current, Action dispose)+MoveNext()
`

[Cinchoo]

Applied fix, released v1.2.1.60

Sample fiddle: https://dotnetfiddle.net/9kp7Aw