feat: implement equality propagation

Cargo.toml

src/errors.rs

src/ir.rs

src/ir/helpers.rs

src/ir/operator.rs

src/ir/tree.rs

src/ir/tree/tests.rs

src/ir/value.rs

src/lib.rs

src/transformation.rs

src/transformation/equality_propagation.rs

src/transformation/equality_propagation/tests.rs

test_app/test/integration/api_test.lua

...actory/transformation/equality_propagation/selection.yaml