parachain-system (#296)

* rename parachain-{upgrade -> system}

* Merge message-broker into parachain-system

* Remove message-broker and clean up

* Update docs

* Test upward messages sending

And also update the relay-sproof-builder so that it allows to set the
relay dispatch queue size for the given parachain.

* Test horizontal message sending

* Remove old inherent definitions

rococo-parachains/contracts-runtime/src/lib.rs

@@ -196,7 +196,7 @@ impl pallet_sudo::Config for Runtime {
 	type Event = Event;
 }
 
-impl cumulus_parachain_upgrade::Config for Runtime {
+impl cumulus_parachain_system::Config for Runtime {
 	type Event = Event;
 	type OnValidationFunctionParams = ();
 }
@@ -260,7 +260,7 @@ construct_runtime! {
 		Contracts: cumulus_pallet_contracts::{Module, Call, Config, Storage, Event<T>},
 		Sudo: pallet_sudo::{Module, Call, Storage, Config<T>, Event<T>},
 		RandomnessCollectiveFlip: pallet_randomness_collective_flip::{Module, Call, Storage},
-		ParachainUpgrade: cumulus_parachain_upgrade::{Module, Call, Storage, Inherent, Event},
+		ParachainUpgrade: cumulus_parachain_system::{Module, Call, Storage, Inherent, Event},
 		MessageBroker: cumulus_message_broker::{Module, Call, Inherent, Event<T>},
 		TokenDealer: cumulus_token_dealer::{Module, Call, Event<T>},
 		TransactionPayment: pallet_transaction_payment::{Module, Storage},