feat: support ORDER BY

doc/sql/query.ebnf

sbroad-cartridge/test_app/test/integration/order_by_test.lua

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

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

sbroad-core/src/executor/bucket.rs

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

sbroad-core/src/executor/ir.rs

sbroad-core/src/executor/protocol.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/ast.rs

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

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

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

sbroad-core/src/frontend/sql/query.pest

sbroad-core/src/ir.rs

sbroad-core/src/ir/api/parameter.rs

sbroad-core/src/ir/distribution.rs

sbroad-core/src/ir/explain.rs