Improve memoization of "ReaderTransitionPage"

- use chapter properties instead of chapter object
- only pass "handleBack" in case the transition page is for the first or last chapter

src/lib/HelperFunctions.ts

@@ -39,3 +39,5 @@ export const getValueFromObject = <T>(obj: Record<string, any>, key: string): T
 };
 
 export const coerceIn = (value: number, min: number, max: number): number => Math.min(Math.max(value, min), max);
+
+export const noOp = () => {};