feat: issue adding add register_udtf and udtf to FunctionRegistry #24

Job	Run time
Check cargo fmt	42s
cargo check	7m 52s
build with wasm-pack	2m 29s
cargo test (macos)	28m 47s
cargo test (macos-aarch64)	11m 0s
Verify MSRV (Min Supported Rust Version)	8m 34s
Verify Vendored Code	51s
cargo test (win64)	43m 26s
clippy	2m 39s
check configs.md is up-to-date	2m 38s
check Cargo.toml formatting	1m 31s
cargo test hash collisions (amd64)	9m 26s
cargo doc	4m 0s
cargo test (amd64)	9m 46s
cargo test datafusion-cli (amd64)	3m 52s
cargo test doc (amd64)	11m 24s
cargo examples (amd64)	8m 51s
Run sqllogictest with Postgres runner	3m 15s
cargo test pyarrow (amd64)	2m 37s
verify benchmark results (amd64)	10m 15s
	2h 53m 55s

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