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/core/chain-selection/src/lib.rs

@@ -51,7 +51,7 @@ type Timestamp = u64;
 // If a block isn't approved in 120 seconds, nodes will abandon it
 // and begin building on another chain.
 const STAGNANT_TIMEOUT: Timestamp = 120;
-// Delay prunning of the stagnant keys in prune only mode by 25 hours to avoid interception with the
+// Delay pruning of the stagnant keys in prune only mode by 25 hours to avoid interception with the
 // finality
 const STAGNANT_PRUNE_DELAY: Timestamp = 25 * 60 * 60;
 // Maximum number of stagnant entries cleaned during one `STAGNANT_TIMEOUT` iteration
@@ -237,7 +237,7 @@ impl Clock for SystemClock {
 		//
 		// The exact time that a block becomes stagnant in the local node is always expected
 		// to differ from other nodes due to network asynchrony and delays in block propagation.
-		// Non-monotonicity exarcerbates that somewhat, but not meaningfully.
+		// Non-monotonicity exacerbates that somewhat, but not meaningfully.
 
 		match SystemTime::now().duration_since(UNIX_EPOCH) {
 			Ok(d) => d.as_secs(),

polkadot/node/core/chain-selection/src/tests.rs

@@ -406,7 +406,7 @@ async fn import_chains_into_empty(
 // some pre-blocks may need to be supplied to answer ancestry requests
 // that gather batches beyond the beginning of the new chain.
 // pre-blocks are those already known by the subsystem, however,
-// the subsystem has no way of knowin that until requesting ancestry.
+// the subsystem has no way of knowing that until requesting ancestry.
 async fn import_all_blocks_into(
 	virtual_overseer: &mut VirtualOverseer,
 	backend: &TestBackend,
@@ -1300,7 +1300,7 @@ fn finalize_erases_unviable_from_one_but_not_all_reverts() {
 		// F <- A1 <- A2 <- A3
 		//
 		// A3 reverts A2 and A1.
-		// Finalize A1. A2 is stil unviable.
+		// Finalize A1. A2 is still unviable.
 
 		let (a3_hash, chain_a) =
 			construct_chain_on_base(vec![1, 2, 3], finalized_number, finalized_hash, |h| {