Make derive types work, and a bit more readable (#1430)

* Fix typings for derive

* Fix typings

* Spacing

packages/api-derive/src/balances/all.ts

@@ -53,7 +53,7 @@ function calcBalances ([accountId = createType('AccountId'), bestNumber = create
     reservedBalance,
     vestedBalance,
     votingBalance: freeBalance.add(reservedBalance)
-  } as unknown as DerivedBalances;
+  } as DerivedBalances;
 }
 
 /**

packages/api-derive/src/balances/fees.ts

@@ -62,7 +62,7 @@ export function fees (api: ApiInterfaceRx): () => Observable<DerivedFees> {
         transactionBaseFee,
         transactionByteFee,
         transferFee
-      } as unknown as DerivedFees)),
+      })),
       drr()
     );
   };