refactor acquisition and renewal pallet-membership

pallets/duniter-wot/src/lib.rs

pallets/duniter-wot/src/tests.rs

pallets/membership/src/benchmarking.rs

pallets/membership/src/lib.rs

pallets/membership/src/tests.rs

primitives/membership/src/lib.rs

runtime/common/src/handlers.rs

runtime/gdev/tests/integration_tests.rs