feat: add avg, min, max, total, group_concat

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

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/ast/tests.rs

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

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

sbroad-core/src/ir/aggregates.rs

sbroad-core/src/ir/explain.rs

sbroad-core/src/ir/function.rs

sbroad-core/src/ir/transformation/redistribution/groupby.rs

...tests/artifactory/frontend/sql/single_quoted_str_ast.yaml