[Python] Support \0 characters in binary Parquet predicate values

As we convert the predicate values of a Parquet filter in some intermediate steps to C-style strings, we currently disallow the use of binary and string predicate values that contain `\0` bytes as they would otherwise result in wrong results.

**Reporter**: [Uwe Korn](https://issues.apache.org/jira/browse/ARROW-3391) / @xhochy

_{**Note**: *This issue was originally created as [ARROW-3391](https://issues.apache.org/jira/browse/ARROW-3391). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}