Test each benchmark case in own #[test] (#9860)

* Generate one #[test] fn per bench case.

* Update benchmark macro syntax in frame pallets.

* Explain new benchmark macro syntax in example pallet.

* support with and without a semicolon

* update pallets to use individual tests

* migrate staking too

* migrate more pallets

* fix up democracy and use individual tests

* Fix comment

* Put println message in panic

* Remove `another_set_dummy` from doc

`another_set_dummy` is not present in the benchmarking.rs (anymore).

* Update doc for benchmarks macro

* Update doc for impl_benchmark_test_suite macro

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

substrate/frame/contracts/src/benchmarking/mod.rs

@@ -36,7 +36,7 @@ use crate::{
 	Pallet as Contracts, *,
 };
 use codec::Encode;
-use frame_benchmarking::{account, benchmarks, impl_benchmark_test_suite, whitelisted_caller};
+use frame_benchmarking::{account, benchmarks, whitelisted_caller};
 use frame_support::weights::Weight;
 use frame_system::RawOrigin;
 use pwasm_utils::parity_wasm::elements::{BlockType, BrTableData, Instruction, ValueType};
@@ -2325,10 +2325,10 @@ benchmarks! {
 		)
 		.result?;
 	}
-}
 
-impl_benchmark_test_suite!(
-	Contracts,
-	crate::tests::ExtBuilder::default().build(),
-	crate::tests::Test,
-);
+	impl_benchmark_test_suite!(
+		Contracts,
+		crate::tests::ExtBuilder::default().build(),
+		crate::tests::Test,
+	)
+}