Use a BoundedVec in ValidationResult (#6603)

* Use a `BoundedVec` in `ValidationResult`

> Use a `BoundedVec` for `upward_messages` and `horizontal_messages` in order to
> limit the number of individual messages/memory allocations right at decoding
> time. The reason for this is that the `ValidationResult` may contain a code
> upgrade (including a full PVF binary), so the total size limit can't be set
> too low and this limit will still allow several millions of upward messages,
> which will (due to the memory allocator overhead) already have a
> non-negligible memory footprint in decoded form.

* List all fields when hashing so we don't miss one

* Define types for  `BoundedVec`s of messages

* Fix test compile errors

* Depend on `bounded-collections` 0.1.4 (fixes allocation issue)

* Fix compilation issue

* Derive `Hash` instead of manual `impl`

* Avoid use of unwrap

polkadot/node/primitives/src/lib.rs

@@ -32,14 +32,14 @@ use serde::{de, Deserialize, Deserializer, Serialize, Serializer};
 use polkadot_primitives::{
 	BlakeTwo256, BlockNumber, CandidateCommitments, CandidateHash, CollatorPair,
 	CommittedCandidateReceipt, CompactStatement, EncodeAs, Hash, HashT, HeadData, Id as ParaId,
-	OutboundHrmpMessage, PersistedValidationData, SessionIndex, Signed, UncheckedSigned,
-	UpwardMessage, ValidationCode, ValidatorIndex, MAX_CODE_SIZE, MAX_POV_SIZE,
+	PersistedValidationData, SessionIndex, Signed, UncheckedSigned, ValidationCode, ValidatorIndex,
+	MAX_CODE_SIZE, MAX_POV_SIZE,
 };
 pub use sp_consensus_babe::{
 	AllowedSlots as BabeAllowedSlots, BabeEpochConfiguration, Epoch as BabeEpoch,
 };
 
-pub use polkadot_parachain::primitives::BlockData;
+pub use polkadot_parachain::primitives::{BlockData, HorizontalMessages, UpwardMessages};
 
 pub mod approval;
 
@@ -312,9 +312,9 @@ impl MaybeCompressedPoV {
 #[cfg(not(target_os = "unknown"))]
 pub struct Collation<BlockNumber = polkadot_primitives::BlockNumber> {
 	/// Messages destined to be interpreted by the Relay chain itself.
-	pub upward_messages: Vec<UpwardMessage>,
+	pub upward_messages: UpwardMessages,
 	/// The horizontal messages sent by the parachain.
-	pub horizontal_messages: Vec<OutboundHrmpMessage<ParaId>>,
+	pub horizontal_messages: HorizontalMessages,
 	/// New validation code.
 	pub new_validation_code: Option<ValidationCode>,
 	/// The head-data produced as a result of execution.