Add Derived Account Origins to Dispatcher (#519)

* Update some docs

* Add derived account origin

* Add tests for derived origin

* Do a little bit of cleanup

* Change Origin type to use AccountIds instead of Public keys

* Update (most) tests to use new Origin types

* Remove redundant test

* Update `runtime-common` tests to use new Origin types

* Remove unused import

* Fix documentation around origin verification

* Update config types to use AccountIds in runtime

* Update Origin type used in message relay

* Use correct type when verifying message origin

* Make CallOrigin docs more consistent

* Use AccountIds instead of Public keys in Runtime types

* Introduce trait for converting AccountIds

* Bring back standalone function for deriving account IDs

* Remove AccountIdConverter configuration trait

* Remove old bridge_account_id derivation function

* Handle target ID decoding errors more gracefully

* Update message-lane to use new AccountId derivation

* Update merged code to use new Origin types

* Use explicit conversion between H256 and AccountIds

* Make relayer fund account a config option in `message-lane` pallet

* Add note about deriving the same account on different chains

* Fix test weight

* Use AccountId instead of Public key when signing Calls

* Semi-hardcode relayer fund address into Message Lane pallet

bridges/primitives/message-dispatch/src/lib.rs

@@ -39,7 +39,7 @@ pub trait MessageDispatch<MessageId> {
 	///
 	/// `bridge` indicates instance of deployed bridge where the message came from.
 	///
-	/// `id` is a short unique if of the message.
+	/// `id` is a short unique identifier of the message.
 	///
 	/// Returns post-dispatch (actual) message weight.
 	fn dispatch(bridge: InstanceId, id: MessageId, message: Self::Message);