Rust

Add SimpleScalarUDF::new_with_signature #396

Job	Run time
Check cargo fmt	41s
build with wasm-pack	2m 5s
Check License Header	2m 12s
cargo check	1m 23s
cargo test (macos)	2m 35s
cargo test (macos-aarch64)	2m 5s
Verify MSRV (Min Supported Rust Version)	5m 25s
Verify Vendored Code	41s
cargo test (win64)	5m 48s
cargo test (amd64)	0s
cargo test datafusion-cli (amd64)	0s
cargo test doc (amd64)	0s
cargo doc	0s
cargo examples (amd64)	0s
Run sqllogictest with Postgres runner	0s
cargo test pyarrow (amd64)	0s
verify benchmark results (amd64)	0s
check Cargo.toml formatting	0s
clippy	0s
check configs.md and ***_functions.md is up-to-date	0s
cargo test hash collisions (amd64)	0s
	22m 55s

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