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.~~

polkadot/node/subsystem-bench/src/lib/network.rs

@@ -154,7 +154,7 @@ pub enum NetworkMessage {
 	MessageFromNode(AuthorityDiscoveryId, VersionedValidationProtocol),
 	/// A request originating from our node
 	RequestFromNode(AuthorityDiscoveryId, Requests),
-	/// A request originating from an emultated peer
+	/// A request originating from an emulated peer
 	RequestFromPeer(IncomingRequest),
 }
 
@@ -790,9 +790,9 @@ pub fn new_network(
 
 	let connected_count = config.connected_count();
 
-	let mut peers_indicies = (0..n_peers).collect_vec();
+	let mut peers_indices = (0..n_peers).collect_vec();
 	let (_connected, to_disconnect) =
-		peers_indicies.partial_shuffle(&mut thread_rng(), connected_count);
+		peers_indices.partial_shuffle(&mut thread_rng(), connected_count);
 
 	// Node under test is always mark as disconnected.
 	peers[NODE_UNDER_TEST as usize].disconnect();
@@ -958,7 +958,7 @@ impl Metrics {
 			.inc_by(bytes as u64);
 	}
 
-	/// Increment total receioved for a peer.
+	/// Increment total received for a peer.
 	pub fn on_peer_received(&self, peer_index: usize, bytes: usize) {
 		self.peer_total_received
 			.with_label_values(vec![format!("node{}", peer_index).as_str()].as_slice())
@@ -1041,7 +1041,7 @@ mod tests {
 	async fn test_expected_rate() {
 		let tick_rate = 200;
 		let budget = 1_000_000;
-		// rate must not exceeed 100 credits per second
+		// rate must not exceed 100 credits per second
 		let mut rate_limiter = RateLimit::new(tick_rate, budget);
 		let mut total_sent = 0usize;
 		let start = Instant::now();