Move runtime upgrade to frame-executive (#5197)

* Move runtime upgrade to `frame-executive`

Instead of storing the runtime upgraded in the space of `frame-system`,
this moves it to `frame-executive`. We also start storing the
`spec_version` and `impl_version` the last runtime upgrade was applied.

This scheme has multiple advantages:
- We don't need to make sure that runtime upgrade was set.
- This will work in the future when we want to test a runtime upgrade,
because the `on_runtime_upgrade` will be executed automatically when the
runtime changes.

* Move `LAST_RUNTIME_UPGRADE` key to `frame-executive`

* Add some more documentation

* Make sure `spec_version` always increases between runtime upgrades

* Fix test

* Upgrade `parity-multiaddr` to fix compilation

* Also check if the `spec_name` changed

* Remove `RuntimeUpgraded` storage entry

* Don't run on genesis

substrate/test-utils/runtime/src/lib.rs

@@ -43,7 +43,7 @@ use sp_runtime::{
 	},
 };
 use sp_version::RuntimeVersion;
-pub use sp_core::{hash::H256};
+pub use sp_core::hash::H256;
 #[cfg(any(feature = "std", test))]
 use sp_version::NativeVersion;
 use frame_support::{impl_outer_origin, parameter_types, weights::Weight};
@@ -64,10 +64,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	spec_name: create_runtime_str!("test"),
 	impl_name: create_runtime_str!("parity-test"),
 	authoring_version: 1,
-	spec_version: 1,
-	#[cfg(feature = "std")]
-	impl_version: 1,
-	#[cfg(not(feature = "std"))]
+	spec_version: 2,
 	impl_version: 2,
 	apis: RUNTIME_API_VERSIONS,
 };