SqlServerStringAggregateMethodTranslator.cs has Size backwards

[timschwallie]

File a bug

If it's unicode the size should be 4000.
This seems to set the size to 8000.
If it's not Unicode, the size should be 8000.
This code below appears to set the size to 4000.

    // STRING_AGG enlarges the return type size (e.g. for input VARCHAR(5), it returns VARCHAR(8000)).
    // See https://docs.microsoft.com/sql/t-sql/functions/string-agg-transact-sql#return-types
    var resultTypeMapping = sqlExpression.TypeMapping;
    if (resultTypeMapping?.Size != null)
    {
        if (**resultTypeMapping.IsUnicode** && resultTypeMapping.Size < 8000)
        {
            resultTypeMapping = _typeMappingSource.FindMapping(
                typeof(string),
                resultTypeMapping.StoreTypeNameBase,
                unicode: true,
                size: 8000);
        }
        else if (**!resultTypeMapping.IsUnicode** && resultTypeMapping.Size < 4000)
        {
            resultTypeMapping = _typeMappingSource.FindMapping(
                typeof(string),
                resultTypeMapping.StoreTypeNameBase,
                unicode: false,
                size: 4000);
        }
    }