Per-things trait. (#4904)

* Give perthigns the trait it always deserved.

* Make staking and phragmen work with the new generic per_thing

* Make everything work together 🔨

* a bit of cleanup

* Clean usage

* Bump.

* Fix name

* fix grumbles

* hopefully fix the ui test

* Some grumbles

* revamp traits again

* Better naming again.

substrate/frame/babe/src/lib.rs

@@ -25,7 +25,7 @@ pub use pallet_timestamp;
 use sp_std::{result, prelude::*};
 use frame_support::{decl_storage, decl_module, traits::{FindAuthor, Get, Randomness as RandomnessT}};
 use sp_timestamp::OnTimestampSet;
-use sp_runtime::{generic::DigestItem, ConsensusEngineId, Perbill};
+use sp_runtime::{generic::DigestItem, ConsensusEngineId, Perbill, PerThing};
 use sp_runtime::traits::{IsMember, SaturatedConversion, Saturating, Hash};
 use sp_staking::{
 	SessionIndex,

substrate/frame/babe/src/mock.rs

@@ -20,7 +20,7 @@
 use super::{Trait, Module, GenesisConfig};
 use sp_consensus_babe::AuthorityId;
 use sp_runtime::{
-	traits::IdentityLookup, Perbill, testing::{Header, UintAuthorityId}, impl_opaque_keys,
+	traits::IdentityLookup, Perbill, PerThing, testing::{Header, UintAuthorityId}, impl_opaque_keys,
 };
 use sp_version::RuntimeVersion;
 use frame_support::{impl_outer_origin, parameter_types, weights::Weight};