Backport to 37: make udf structs public #25772

Job	Run time
cargo check	10m 14s
cargo test (macos)	38m 12s
build with wasm-pack	2m 25s
cargo test (macos-aarch64)	10m 19s
Verify Vendored Code	55s
cargo test (win64)	44m 49s
Check cargo fmt	42s
Verify MSRV (Min Supported Rust Version)	7m 0s
cargo test (amd64)	10m 19s
cargo test datafusion-cli (amd64)	3m 48s
cargo doc	4m 6s
cargo test doc (amd64)	13m 8s
cargo examples (amd64)	11m 2s
Run sqllogictest with Postgres runner	3m 15s
cargo test pyarrow (amd64)	2m 41s
verify benchmark results (amd64)	10m 7s
check Cargo.toml formatting	3m 4s
clippy	5m 52s
check configs.md is up-to-date	2m 36s
cargo test hash collisions (amd64)	10m 2s
	3h 14m 36s

Provide feedback