arrow

ARROW-12043: [Rust] [Parquet] Write FSB arrays

Minor change to compute the levels for FSB arrays and write them out. Added a roundtrip test.

Closes #9771 from nevi-me/ARROW-12043

Authored-by: Neville Dipale <nevilledips@gmail.com>
Signed-off-by: Neville Dipale <nevilledips@gmail.com>