Fix spelling mistakes across the whole repository (#3808)

**Update:** Pushed additional changes based on the review comments.

**This pull request fixes various spelling mistakes in this
repository.**

Most of the changes are contained in the first **3** commits:

- `Fix spelling mistakes in comments and docs`

- `Fix spelling mistakes in test names`

- `Fix spelling mistakes in error messages, panic messages, logs and
tracing`

Other source code spelling mistakes are separated into individual
commits for easier reviewing:

- `Fix the spelling of 'authority'`

- `Fix the spelling of 'REASONABLE_HEADERS_IN_JUSTIFICATION_ANCESTRY'`

- `Fix the spelling of 'prev_enqueud_messages'`

- `Fix the spelling of 'endpoint'`

- `Fix the spelling of 'children'`

- `Fix the spelling of 'PenpalSiblingSovereignAccount'`

- `Fix the spelling of 'PenpalSudoAccount'`

- `Fix the spelling of 'insufficient'`

- `Fix the spelling of 'PalletXcmExtrinsicsBenchmark'`

- `Fix the spelling of 'subtracted'`

- `Fix the spelling of 'CandidatePendingAvailability'`

- `Fix the spelling of 'exclusive'`

- `Fix the spelling of 'until'`

- `Fix the spelling of 'discriminator'`

- `Fix the spelling of 'nonexistent'`

- `Fix the spelling of 'subsystem'`

- `Fix the spelling of 'indices'`

- `Fix the spelling of 'committed'`

- `Fix the spelling of 'topology'`

- `Fix the spelling of 'response'`

- `Fix the spelling of 'beneficiary'`

- `Fix the spelling of 'formatted'`

- `Fix the spelling of 'UNKNOWN_PROOF_REQUEST'`

- `Fix the spelling of 'succeeded'`

- `Fix the spelling of 'reopened'`

- `Fix the spelling of 'proposer'`

- `Fix the spelling of 'InstantiationNonce'`

- `Fix the spelling of 'depositor'`

- `Fix the spelling of 'expiration'`

- `Fix the spelling of 'phantom'`

- `Fix the spelling of 'AggregatedKeyValue'`

- `Fix the spelling of 'randomness'`

- `Fix the spelling of 'defendant'`

- `Fix the spelling of 'AquaticMammal'`

- `Fix the spelling of 'transactions'`

- `Fix the spelling of 'PassingTracingSubscriber'`

- `Fix the spelling of 'TxSignaturePayload'`

- `Fix the spelling of 'versioning'`

- `Fix the spelling of 'descendant'`

- `Fix the spelling of 'overridden'`

- `Fix the spelling of 'network'`

Let me know if this structure is adequate.

**Note:** The usage of the words `Merkle`, `Merkelize`, `Merklization`,
`Merkelization`, `Merkleization`, is somewhat inconsistent but I left it
as it is.

~~**Note:** In some places the term `Receival` is used to refer to
message reception, IMO `Reception` is the correct word here, but I left
it as it is.~~

~~**Note:** In some places the term `Overlayed` is used instead of the
more acceptable version `Overlaid` but I also left it as it is.~~

~~**Note:** In some places the term `Applyable` is used instead of the
correct version `Applicable` but I also left it as it is.~~

**Note:** Some usage of British vs American english e.g. `judgement` vs
`judgment`, `initialise` vs `initialize`, `optimise` vs `optimize` etc.
are both present in different places, but I suppose that's
understandable given the number of contributors.

~~**Note:** There is a spelling mistake in `.github/CODEOWNERS` but it
triggers errors in CI when I make changes to it, so I left it as it
is.~~

substrate/client/network/src/protocol/notifications/behaviour.rs

@@ -2668,7 +2668,7 @@ mod tests {
 		//
 		// there is not straight-forward way of adding backoff to `PeerState::Disabled`
 		// so manually adjust the value in order to progress on to the next stage.
-		// This modification together with `ConnectionClosed` will conver the peer
+		// This modification together with `ConnectionClosed` will convert the peer
 		// state into `PeerState::Backoff`.
 		if let Some(PeerState::Disabled { ref mut backoff_until, .. }) =
 			notif.peers.get_mut(&(peer, set_id))

substrate/client/network/src/protocol/notifications/handler.rs

@@ -211,7 +211,7 @@ enum State {
 	/// consequently trying to open the various notifications substreams.
 	///
 	/// A [`NotifsHandlerOut::OpenResultOk`] or a [`NotifsHandlerOut::OpenResultErr`] event must
-	/// be emitted when transitionning to respectively [`State::Open`] or [`State::Closed`].
+	/// be emitted when transitioning to respectively [`State::Open`] or [`State::Closed`].
 	Opening {
 		/// Substream opened by the remote. If `Some`, has been accepted.
 		in_substream: Option<NotificationsInSubstream<NegotiatedSubstream>>,

substrate/client/network/src/protocol/notifications/service/mod.rs

@@ -54,7 +54,7 @@ const COMMAND_QUEUE_SIZE: usize = 64;
 /// Type representing subscribers of a notification protocol.
 type Subscribers = Arc<Mutex<Vec<TracingUnboundedSender<InnerNotificationEvent>>>>;
 
-/// Type represending a distributable message sink.
+/// Type representing a distributable message sink.
 /// Detached message sink must carry the protocol name for registering metrics.
 ///
 /// See documentation for [`PeerContext`] for more details.
@@ -175,11 +175,11 @@ pub enum NotificationCommand {
 /// and an additional, distributable `NotificationsSink` which the protocol may acquire
 /// if it wishes to send notifications through `NotificationsSink` directly.
 ///
-/// The distributable `NoticationsSink` is wrapped in an `Arc<Mutex<>>` to allow
+/// The distributable `NotificationsSink` is wrapped in an `Arc<Mutex<>>` to allow
 /// `NotificationsService` to swap the underlying sink in case it's replaced.
 #[derive(Debug, Clone)]
 struct PeerContext {
-	/// Sink for sending notificaitons.
+	/// Sink for sending notifications.
 	sink: NotificationsSink,
 
 	/// Distributable notification sink.

substrate/client/network/src/protocol/notifications/service/tests.rs

@@ -437,7 +437,7 @@ async fn peer_disconnects_then_async_notification_is_sent() {
 		notif.send_async_notification(&peer_id, vec![1, 3, 3, 7]).await
 	{
 	} else {
-		panic!("invalid state after calling `send_async_notificatio()` on closed connection")
+		panic!("invalid state after calling `send_async_notification()` on closed connection")
 	}
 }
 

substrate/client/network/src/protocol/notifications/upgrade/notifications.rs

@@ -188,7 +188,7 @@ where
 	}
 }
 
-/// Yielded by the [`NotificationsIn`] after a successfuly upgrade.
+/// Yielded by the [`NotificationsIn`] after a successfully upgrade.
 pub struct NotificationsInOpen<TSubstream> {
 	/// Handshake sent by the remote.
 	pub handshake: Vec<u8>,
@@ -415,7 +415,7 @@ where
 	}
 }
 
-/// Yielded by the [`NotificationsOut`] after a successfuly upgrade.
+/// Yielded by the [`NotificationsOut`] after a successfully upgrade.
 pub struct NotificationsOutOpen<TSubstream> {
 	/// Handshake returned by the remote.
 	pub handshake: Vec<u8>,