Remove `Transformed` enum #22014

Job	Run time
cargo check	2m 19s
cargo test (mac)	20m 52s
build with wasm-pack	1m 57s
Check cargo fmt	38s
Verify MSRV	6m 12s
cargo test (win64)	39m 21s
Verify Vendored Code	43s
cargo test datafusion-cli (amd64)	2m 58s
cargo test hash collisions (amd64)	8m 21s
cargo doc	3m 7s
clippy	4m 12s
cargo test (amd64)	8m 30s
cargo test doc (amd64)	9m 18s
cargo examples (amd64)	6m 50s
Run sqllogictest with Postgres runner	3m 5s
cargo test pyarrow (amd64)	2m 5s
verify benchmark results (amd64)	9m 36s
check Cargo.toml formatting	3m 2s
check configs.md is up-to-date	2m 17s
	2h 15m 23s

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