cast Utf8 to decimal failure

[Weijun-H]

Describe the bug

arrow cannot cast Utf8 to decimal correctly in #8326.

// Negative number is wrong
❯ select '-1.23499999'::DECIMAL(4,3);
+---------------------+
| Utf8("-1.23499999") |
+---------------------+
| -0.765              |
+---------------------+
1 row in set. Query took 0.032 seconds.

The problem is that arrow does not parse the string correctly.
fn parse_string_to_decimal_native<T: DecimalType>(

To Reproduce

    #[test]
    fn test() {
        let array = LargeStringArray::from(vec![Some("-0.12345")]);

        // Decimal128
        let output_type = DataType::Decimal128(38, 2);
        assert!(can_cast_types(array.data_type(), &output_type));

        let casted_array = cast(&array, &output_type).unwrap();
        let decimal_arr = casted_array.as_primitive::<Decimal128Type>();

        assert_eq!("-0.12", decimal_arr.value_as_string(0));

        // Decimal256
        let output_type = DataType::Decimal256(76, 3);
        assert!(can_cast_types(array.data_type(), &output_type));

        let casted_array = cast(&array, &output_type).unwrap();
        let decimal_arr = casted_array.as_primitive::<Decimal256Type>();

        assert_eq!("-0.123.", decimal_arr.value_as_string(0));
    }

Expected behavior

pass the test

Additional context

#8326

[tustvold]

Looks like this is adding 1 instead of -1 when combining the decimal and numeric components

[tustvold]

label_issue.py automatically added labels {'arrow'} from #5128