New sessions, kill consensus module (#2802)

* Draft of new sessions

* Reintroduce tuple impls

* Move staking module to new session API

* More work on staking and grandpa.

* Use iterator to avoid cloning and tuple macro

* Make runtime build again

* Polish the OpaqueKeys devex

* Move consensus logic into system & aura.

* Fix up system module

* Get build mostly going. Stuck at service.rs

* Building again

* Update srml/staking/src/lib.rs

Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com>

* Refactoring out Consensus module, AuthorityIdOf, &c.

* Refactored out DigestItem::AuthoritiesChanged. Building.

* Remove tentative code

* Remove invalid comment

* Make Seal opaque and introduce nice methods for handling opaque items.

* Start to use proper digest for Aura authorities tracking.

* Fix up grandpa, remove system::Raw/Log

* Refactor Grandpa to use new logging infrastructure.

Also make authorityid/sessionkey static. Switch over to storing
authorities in a straight Vec.

* Building again

* Tidy up some AuthorityIds

* Expunge most of the rest of the AuthorityKey confusion.

Also, de-generify Babe and re-generify Aura.

* Remove cruft

* Untangle last of the `AuthorityId`s.

* Sort out finality_tracker

* Refactor median getting

* Apply suggestions from code review

Co-Authored-By: Robert Habermeier <rphmeier@gmail.com>

* Session tests works

* Update core/sr-primitives/src/generic/digest.rs

Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com>

* Session tests works

* Fix for staking from @dvc94ch

* log an error

* fix test runtime build

* Some test fixes

* Staking mock update to new session api.

* Fix build.

* Move OpaqueKeys to primitives.

* Use on_initialize instead of check_rotate_session.

* Update tests to new staking api.

* fixup mock

* Fix bond_extra_and_withdraw_unbonded_works.

* Fix bond_with_little_staked_value_bounded_by_slot_stake.

* Fix bond_with_no_staked_value.

* Fix change_controller_works.

* Fix less_than_needed_candidates_works.

* Fix multi_era_reward_should_work.

* Fix nominating_and_rewards_should_work.

* Fix nominators_also_get_slashed.

* Fix phragmen_large_scale_test.

* Fix phragmen_poc_works.

* Fix phragmen_score_should_be_accurate_on_large_stakes.

* Fix phragmen_should_not_overflow.

* Fix reward_destination_works.

* Fix rewards_should_work.

* Fix sessions_and_eras_should_work.

* Fix slot_stake_is_least_staked_validator.

* Fix too_many_unbond_calls_should_not_work.

* Fix wrong_vote_is_null.

* Fix runtime.

* Fix wasm runtime build.

* Update Cargo.lock

* Fix warnings.

* Fix grandpa tests.

* Fix test-runtime build.

* Fix template node build.

* Fix stuff.

* Update Cargo.lock to fix CI

* Re-add missing AuRa logs

Runtimes are required to know about every digest they receive ― they
panic otherwise.  This re-adds support for AuRa pre-runtime digests.

* Update core/consensus/babe/src/digest.rs

Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com>

* Kill log trait and all that jazz.

* Refactor staking tests.

* Fix ci runtime wasm check.

* Line length 120.

* Make tests build again

* Remove trailing commas in function declarations

The `extern_functions!` macro doesn’t like them, perhaps due to a bug in
rustc.

* Fix type error

* Fix compilation errors

* Fix a test

* Another couple of fixes

* Fix another test

* More test fixes

* Another test fix

* Bump runtime.

* Wrap long line

* Fix build, remove redundant code.

* Issue to track TODO

* Leave the benchmark code alone.

* Fix missing `std::time::{Instant, Duration}`

* Indentation

* Aura ConsensusLog as enum

substrate/srml/support/procedural/src/storage/impls.rs

@@ -122,7 +122,11 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 				}
 
 				/// Mutate the value under a key.
-				fn mutate<R, F: FnOnce(&mut Self::Query) -> R, S: #scrate::HashedStorage<#scrate::Twox128>>(f: F, storage: &mut S) -> R {
+				fn mutate<R, F, S>(f: F, storage: &mut S) -> R
+				where
+					F: FnOnce(&mut Self::Query) -> R,
+					S: #scrate::HashedStorage<#scrate::Twox128>,
+				{
 					let mut val = <Self as #scrate::storage::hashed::generator::StorageValue<#typ>>::get(storage);
 
 					let ret = f(&mut val);
@@ -218,7 +222,11 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 				}
 
 				/// Mutate the value under a key
-				fn mutate<R, F: FnOnce(&mut Self::Query) -> R, S: #scrate::HashedStorage<#scrate::#hasher>>(key: &#kty, f: F, storage: &mut S) -> R {
+				fn mutate<R, F, S>(key: &#kty, f: F, storage: &mut S) -> R
+				where
+					F: FnOnce(&mut Self::Query) -> R,
+					S: #scrate::HashedStorage<#scrate::#hasher>,
+				{
 					let mut val = #as_map::get(key, storage);
 
 					let ret = f(&mut val);
@@ -355,7 +363,9 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 					fn remove_linkage<S: #scrate::HashedStorage<#scrate::#hasher>>(linkage: Linkage<#kty>, storage: &mut S);
 
 					/// Read the contained data and it's linkage.
-					fn read_with_linkage<S: #scrate::HashedStorage<#scrate::#hasher>>(storage: &S, key: &[u8]) -> Option<(#value_type, Linkage<#kty>)>;
+					fn read_with_linkage<S>(storage: &S, key: &[u8]) -> Option<(#value_type, Linkage<#kty>)>
+					where
+						S: #scrate::HashedStorage<#scrate::#hasher>;
 
 					/// Generate linkage for newly inserted element.
 					///
@@ -525,7 +535,11 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 				}
 
 				/// Mutate the value under a key
-				fn mutate<R, F: FnOnce(&mut Self::Query) -> R, S: #scrate::HashedStorage<#scrate::#hasher>>(key: &#kty, f: F, storage: &mut S) -> R {
+				fn mutate<R, F, S>(key: &#kty, f: F, storage: &mut S) -> R
+				where
+					F: FnOnce(&mut Self::Query) -> R,
+					S: #scrate::HashedStorage<#scrate::#hasher>,
+				{
 					use self::#inner_module::Utils;
 
 					let key_for = &*#as_map::key_for(key);
@@ -548,7 +562,9 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 					Self::read_head(storage)
 				}
 
-				fn enumerate<'a, S: #scrate::HashedStorage<#scrate::#hasher>>(storage: &'a S) -> #scrate::rstd::boxed::Box<dyn Iterator<Item = (#kty, #typ)> + 'a> where
+				fn enumerate<'a, S>(storage: &'a S) -> #scrate::rstd::boxed::Box<dyn Iterator<Item = (#kty, #typ)> + 'a>
+				where
+					S: #scrate::HashedStorage<#scrate::#hasher>,
 					#kty: 'a,
 					#typ: 'a,
 				{
@@ -564,7 +580,13 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 		}
 	}
 
-	pub fn double_map(self, hasher: TokenStream2, k1ty: &syn::Type, k2ty: &syn::Type, k2_hasher: TokenStream2) -> TokenStream2 {
+	pub fn double_map(
+		self,
+		hasher: TokenStream2,
+		k1ty: &syn::Type,
+		k2ty: &syn::Type,
+		k2_hasher: TokenStream2,
+	) -> TokenStream2 {
 		let Self {
 			scrate,
 			visibility,
@@ -653,7 +675,11 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 					storage.take(&key).#option_simple_1(|| #fielddefault)
 				}
 
-				fn mutate<R, F: FnOnce(&mut Self::Query) -> R, S: #scrate::UnhashedStorage>(key1: &#k1ty, key2: &#k2ty, f: F, storage: &mut S) -> R {
+				fn mutate<R, F, S>(key1: &#k1ty, key2: &#k2ty, f: F, storage: &mut S) -> R
+				where
+					F: FnOnce(&mut Self::Query) -> R,
+					S: #scrate::UnhashedStorage,
+				{
 					let mut val = #as_double_map::get(key1, key2, storage);
 
 					let ret = f(&mut val);