Coretime Feature branch (relay chain) (#1694)

Also fixes: https://github.com/paritytech/polkadot-sdk/issues/1417

- [x] CoreIndex -> AssignmentProvider mapping will be able to change any
time.
- [x] Implement
- [x] Provide Migrations
- [x] Add and fix tests
- [x] Implement bulk assigner logic
- [x] bulk assigner tests
- [x] Port over current assigner to use bulk designer (+ share on-demand
with bulk): top-level assigner has core ranges: legacy, bulk
- [x] Adjust migrations to reflect new assigner structure
- [x] Move migration code to Assignment code directly and make it
recursive (make it possible to skip releases) -> follow up ticket.
- [x] Test migrations
- [x] Add migration PR to runtimes repo -> follow up ticket.
- [x] Wire up with actual UMP messages
- [x] Write PR docs

---------

Co-authored-by: eskimor <eskimor@no-such-url.com>
Co-authored-by: Bradley Olson <34992650+BradleyOlson64@users.noreply.github.com>
Co-authored-by: BradleyOlson64 <lotrftw9@gmail.com>
Co-authored-by: Anton Vilhelm Ásgeirsson <antonva@users.noreply.github.com>
Co-authored-by: antonva <anton.asgeirsson@parity.io>
Co-authored-by: Bastian Köcher <git@kchr.de>
Co-authored-by: Marcin S. <marcin@realemail.net>
Co-authored-by: Bastian Köcher <info@kchr.de>
Co-authored-by: command-bot <>

polkadot/runtime/test-runtime/src/lib.rs

@@ -74,7 +74,7 @@ use sp_runtime::{
 		SaturatedConversion, StaticLookup, Verify,
 	},
 	transaction_validity::{TransactionPriority, TransactionSource, TransactionValidity},
-	ApplyExtrinsicResult, KeyTypeId, Perbill,
+	ApplyExtrinsicResult, FixedU128, KeyTypeId, Perbill,
 };
 use sp_staking::SessionIndex;
 #[cfg(any(feature = "std", test))]
@@ -520,6 +520,7 @@ impl parachains_initializer::Config for Runtime {
 	type Randomness = pallet_babe::RandomnessFromOneEpochAgo<Runtime>;
 	type ForceOrigin = frame_system::EnsureRoot<AccountId>;
 	type WeightInfo = ();
+	type CoretimeOnNewSession = ();
 }
 
 impl parachains_session_info::Config for Runtime {
@@ -537,6 +538,15 @@ impl parachains_paras::Config for Runtime {
 	type QueueFootprinter = ParaInclusion;
 	type NextSessionRotation = Babe;
 	type OnNewHead = ();
+	type AssignCoretime = ();
+}
+
+parameter_types! {
+	pub const BrokerId: u32 = 10u32;
+}
+
+parameter_types! {
+	pub const OnDemandTrafficDefaultValue: FixedU128 = FixedU128::from_u32(1);
 }
 
 impl parachains_dmp::Config for Runtime {}