feat: add benchmarks and improve performance

Cargo.toml

benches/engine.rs

benches/parse.rs

src/executor.rs

src/executor/bucket.rs

src/executor/engine/cartridge/backend/sql/ir.rs

src/executor/engine/cartridge/backend/sql/tree.rs

src/executor/engine/mock.rs

src/executor/ir.rs

src/executor/result.rs

src/executor/vtable.rs

src/frontend/sql/grammar.pest

src/frontend/sql/ir.rs

src/ir.rs

src/ir/distribution.rs

src/ir/expression.rs

src/ir/operator.rs

src/ir/transformation.rs

src/ir/transformation/dnf.rs

src/ir/transformation/equality_propagation.rs