fix: refactoring after rebase on new protocol, tiers and subarenas

sbroad-core/src/backend/sql/ir.rs

sbroad-core/src/backend/sql/ir/tests/selection.rs

sbroad-core/src/backend/sql/space.rs

sbroad-core/src/backend/sql/tree.rs

sbroad-core/src/executor/engine/helpers.rs

sbroad-core/src/executor/ir.rs

sbroad-core/src/executor/result.rs

sbroad-core/src/executor/tests.rs

sbroad-core/src/executor/tests/exec_plan.rs

sbroad-core/src/frontend/sql.rs

sbroad-core/src/frontend/sql/ir/tests.rs

sbroad-core/src/frontend/sql/ir/tests/global.rs

sbroad-core/src/frontend/sql/ir/tests/limit.rs

sbroad-core/src/ir.rs

sbroad-core/src/ir/distribution/tests.rs

sbroad-core/src/ir/explain.rs

sbroad-core/src/ir/expression.rs

sbroad-core/src/ir/helpers.rs

sbroad-core/src/ir/helpers/tests.rs

sbroad-core/src/ir/node.rs