Rust

adding expr to string for IsNotNull IsTrue IsFalse and IsUnkown #24826

Job	Run time
build with wasm-pack	2m 16s
cargo check	4m 49s
cargo test (macos)	22m 56s
cargo test (macos-aarch64)	12m 20s
cargo test (win64)	44m 43s
Check cargo fmt	45s
Verify MSRV (Min Supported Rust Version)	7m 22s
Verify Vendored Code	1m 9s
cargo test (amd64)	10m 37s
cargo test doc (amd64)	12m 39s
cargo examples (amd64)	10m 23s
cargo test datafusion-cli (amd64)	3m 40s
check Cargo.toml formatting	2m 56s
clippy	5m 38s
cargo test hash collisions (amd64)	10m 6s
cargo doc	4m 3s
Run sqllogictest with Postgres runner	3m 22s
cargo test pyarrow (amd64)	2m 34s
verify benchmark results (amd64)	10m 43s
check configs.md is up-to-date	2m 29s
	2h 55m 30s

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