Avoid RowConverter for multi column grouping (10% faster clickbench queries) #32381

Job	Run time
cargo check	6m 4s
build with wasm-pack	2m 32s
cargo test (win64)	11m 37s
Check cargo fmt	31s
cargo test (macos)	5m 44s
cargo test (macos-aarch64)	4m 39s
Verify MSRV (Min Supported Rust Version)	6m 58s
Verify Vendored Code	53s
cargo examples (amd64)	13m 4s
cargo test doc (amd64)	14m 36s
cargo test datafusion-cli (amd64)	3m 46s
cargo test (amd64)	7m 11s
cargo doc	3m 46s
Run sqllogictest with Postgres runner	3m 32s
cargo test pyarrow (amd64)	3m 0s
verify benchmark results (amd64)	11m 54s
check Cargo.toml formatting	2m 47s
clippy	5m 16s
check configs.md is up-to-date	2m 39s
cargo test hash collisions (amd64)	6m 39s
	1h 57m 8s

Provide feedback