[BUG]: Error unpickling decimal array when array contains at least one '0' value

**Describe the bug**
Parquet file has a column of array>. If row has an array such as **array(0,1,2,3)** we will get an exception under certain situations. The exception only happens when the array itself contains at least 1 element whose value is 0.

**To Reproduce**

Create a parquet file described as above then read it into a DF.

From the C# side do something like:

```
var df = spark.read.parquet("path to file")
var rows = df.toLocalIterator();
```

Once you try to enumerate rows you'll get the following exception:

```
Unhandled exception. System.FormatException: Input string was not in a correct format.
at System.Number.ThrowOverflowOrFormatException(ParsingStatus status, TypeCode type)
at System.Convert.ToDecimal(String value, IFormatProvider provider)
at Razorvine.Pickle.Objects.DecimalConstructor.construct(Object[] args)
at Razorvine.Pickle.UnpicklerImplementation`1.load_reduce()
at Razorvine.Pickle.UnpicklerImplementation`1.Dispatch(Byte key)
at Razorvine.Pickle.UnpicklerImplementation`1.Load()
at Razorvine.Pickle.Unpickler.loads(Byte[] pickledata, Int32 stackCapacity)
at Razorvine.Pickle.Unpickler.loads(ReadOnlyMemory`1 pickledata, Int32 stackCapacity)
at Microsoft.Spark.Utils.PythonSerDe.GetUnpickledObjects(Stream stream, Int32 messageLength) in /mnt/c/Users/adam/Repos/spark/src/csharp/Microsoft.Spark/Utils/PythonSerDe.cs:line 65
at Microsoft.Spark.Sql.RowCollector.Collect(ISocketWrapper socket)+MoveNext() in /mnt/c/Users/adam/Repos/spark/src/csharp/Microsoft.Spark/Sql/RowCollector.cs:line 33
at Microsoft.Spark.Sql.RowCollector.LocalIteratorFromSocket.GetEnumerator()+MoveNext() in /mnt/c/Users/adam/Repos/spark/src/csharp/Microsoft.Spark/Sql/RowCollector.cs:line 117
at Microsoft.Spark.Sql.DataFrame.ToLocalIterator(Boolean prefetchPartitions)+MoveNext() in /mnt/c/Users/adam/Repos/spark/src/csharp/Microsoft.Spark/Sql/DataFrame.cs:line 843
```

This currently is happening with v1.0.0.