Rust

Add null tests #79

Job	Run time
cargo check	5m 41s
Check cargo fmt	32s
build with wasm-pack	2m 33s
cargo test (macos)	10m 24s
cargo test (macos-aarch64)	11m 20s
Verify MSRV (Min Supported Rust Version)	6m 55s
Verify Vendored Code	41s
cargo test (win64)	43m 59s
cargo test (amd64)	10m 14s
clippy	6m 4s
cargo test doc (amd64)	14m 41s
cargo doc	3m 55s
cargo test datafusion-cli (amd64)	3m 50s
cargo examples (amd64)	13m 43s
Run sqllogictest with Postgres runner	3m 48s
verify benchmark results (amd64)	12m 10s
cargo test pyarrow (amd64)	3m 7s
check Cargo.toml formatting	2m 59s
check configs.md is up-to-date	2m 59s
cargo test hash collisions (amd64)	14m 13s
	2h 53m 48s

Provide feedback