Parquet bool column SortOrder being UNSIGNED?

**Describe the bug**
Hi, please close if it's intended. It seems that SortOrder for bool is [UNSIGNED](https://github.com/jp0317/arrow-rs/blob/master/parquet/src/basic.rs#L625) in rust but [SIGNED](https://github.com/apache/arrow/blob/main/cpp/src/parquet/types.cc#L272-L277) in c++ implementation. Should the rust implementation also be SIGNED?

**To Reproduce**
n/a

**Expected behavior**
Consistency?

**Additional context**
n/a

Start in parquet/src/basic.rs at the bool SortOrder definition, then compare it with the referenced C++ implementation in cpp/src/parquet/types.cc. Determine whether the Rust and C++ behaviors should agree, and consider the relevant Parquet semantics; the issue is done when the intended bool SortOrder is established and the Rust behavior is consistent with it.

Written by the indexing model from the issue text.