Add Authorize Upgrade Pattern to Frame System (#2682)

Adds the `authorize_upgrade` -> `enact_authorized_upgrade` pattern to
`frame-system`. This will be useful for upgrading bridged chains that
are under the governance of Polkadot without passing entire runtime Wasm
blobs over a bridge.

Notes:

- Changed `enact_authorized_upgrade` to `apply_authorized_upgrade`.
Personal opinion, "apply" more accurately expresses what it's doing. Can
change back if outvoted.
- Remove `check_version` in favor of two extrinsics, so as to make
_checked_ the default.
- Left calls in `parachain-system` and marked as deprecated to prevent
breaking the API. They just call into the `frame-system` functions.
- Updated `frame-system` benchmarks to v2 syntax.

---------

Co-authored-by: command-bot <>

substrate/frame/support/test/tests/pallet_outer_enums_explicit.rs

@@ -94,6 +94,8 @@ fn module_error_outer_enum_expand_explicit() {
 			frame_system::Error::InvalidTask => (),
 			#[cfg(feature = "experimental")]
 			frame_system::Error::FailedTask => (),
+			frame_system::Error::NothingAuthorized => (),
+			frame_system::Error::Unauthorized => (),
 			frame_system::Error::__Ignore(_, _) => (),
 		},
 

substrate/frame/support/test/tests/pallet_outer_enums_implicit.rs

@@ -94,6 +94,8 @@ fn module_error_outer_enum_expand_implicit() {
 			frame_system::Error::InvalidTask => (),
 			#[cfg(feature = "experimental")]
 			frame_system::Error::FailedTask => (),
+			frame_system::Error::NothingAuthorized => (),
+			frame_system::Error::Unauthorized => (),
 			frame_system::Error::__Ignore(_, _) => (),
 		},