[Go] Decimal type is being returned as string

[Mandukhai-Alimaa]

FAILED validation/tests/test_query.py::TestQuery::test_query[databricks:v1.9.0:type/literal/decimal] - AssertionError: Field types do not match: res (decimal128(10, 2)) != res (string)
assert Decimal128Type(decimal128(10, 2)) == DataType(string)
 +  where Decimal128Type(decimal128(10, 2)) = pyarrow.Field<res: decimal128(10, 2)>.type
 +  and   DataType(string) = pyarrow.Field<res: string>.type
FAILED validation/tests/test_query.py::TestQuery::test_query[databricks:v1.9.0:type/select/decimal] - AssertionError: Field types do not match: res (decimal128(10, 2)) != res (string)
assert Decimal128Type(decimal128(10, 2)) == DataType(string)
 +  where Decimal128Type(decimal128(10, 2)) = pyarrow.Field<res: decimal128(10, 2)>.type
 +  and   DataType(string) = pyarrow.Field<res: string>.type