Fix for RPC bugs caused by uk spelling (#904)

* Replaced UK with US spelling

* -ised to -ized

* UK -> US spelling in chain rpc methods

* Tests for RPC chain methods on Alex

packages/api-derive/src/chain/bestNumberFinalized.ts

@@ -10,13 +10,13 @@ import { BlockNumber, Header } from '@polkadot/types';
 import { drr } from '../util/drr';
 
 /**
- * @description Get the latest finalised block number.
+ * @description Get the latest finalized block number.
  * example
  * <BR>
  *
  * ```javascript
  * api.derive.chain.bestNumberFinalized((blockNumber) => {
- *   console.log(`the current finalised block is #${blockNumber}`);
+ *   console.log(`the current finalized block is #${blockNumber}`);
  * });
  * ```
  */

packages/api-derive/src/chain/bestNumberLag.ts

@@ -12,13 +12,13 @@ import { bestNumber } from './bestNumber';
 import { bestNumberFinalized } from './bestNumberFinalized';
 
 /**
- * @description Calculates the lag between finalised head and best head
+ * @description Calculates the lag between finalized head and best head
  * @example
  * <BR>
  *
  * ```javascript
  * api.derive.chain.bestNumberLag((lag) => {
- *   console.log(`finalised is ${lag} blocks behind head`);
+ *   console.log(`finalized is ${lag} blocks behind head`);
  * });
  * ```
  */