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/primitives/src/approval.rs

@@ -382,7 +382,7 @@ pub mod v2 {
 			/// The core index chosen in this cert.
 			core_index: CoreIndex,
 		},
-		/// Deprectated assignment. Soon to be removed.
+		/// Deprecated assignment. Soon to be removed.
 		///  An assignment story based on the VRF that authorized the relay-chain block where the
 		/// candidate was included combined with a sample number.
 		///

polkadot/node/primitives/src/disputes/mod.rs

@@ -84,7 +84,7 @@ impl CandidateVotes {
 #[derive(Debug, Clone)]
 /// Valid candidate votes.
 ///
-/// Prefere backing votes over other votes.
+/// Prefer backing votes over other votes.
 pub struct ValidCandidateVotes {
 	votes: BTreeMap<ValidatorIndex, (ValidDisputeStatementKind, ValidatorSignature)>,
 }
@@ -133,7 +133,7 @@ impl ValidCandidateVotes {
 		self.votes.retain(f)
 	}
 
-	/// Get all the validator indeces we have votes for.
+	/// Get all the validator indices we have votes for.
 	pub fn keys(
 		&self,
 	) -> Bkeys<'_, ValidatorIndex, (ValidDisputeStatementKind, ValidatorSignature)> {

polkadot/node/primitives/src/lib.rs

@@ -74,7 +74,7 @@ pub const VALIDATION_CODE_BOMB_LIMIT: usize = (MAX_CODE_SIZE * 4u32) as usize;
 pub const POV_BOMB_LIMIT: usize = (MAX_POV_SIZE * 4u32) as usize;
 
 /// How many blocks after finalization an information about backed/included candidate should be
-/// pre-loaded (when scraoing onchain votes) and kept locally (when pruning).
+/// pre-loaded (when scraping onchain votes) and kept locally (when pruning).
 ///
 /// We don't want to remove scraped candidates on finalization because we want to
 /// be sure that disputes will conclude on abandoned forks.