Moves all test runtimes to use derive_impl (#2409)

Step in https://github.com/paritytech/polkadot-sdk/issues/171

This PR adds `derive_impl` on all `frame_system` config impls for mock
runtimes. The overridden configs are maintained as of now to ensure
minimal changes.

---------

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

substrate/frame/offences/benchmarking/src/mock.rs

@@ -25,7 +25,7 @@ use frame_election_provider_support::{
 	onchain, SequentialPhragmen,
 };
 use frame_support::{
-	parameter_types,
+	derive_impl, parameter_types,
 	traits::{ConstU32, ConstU64},
 };
 use frame_system as system;
@@ -40,6 +40,7 @@ type AccountId = u64;
 type Nonce = u32;
 type Balance = u64;
 
+#[derive_impl(frame_system::config_preludes::TestDefaultConfig as frame_system::DefaultConfig)]
 impl frame_system::Config for Test {
 	type BaseCallFilter = frame_support::traits::Everything;
 	type BlockWeights = ();