* feat: add validation for null values in bookingFieldsResponses
- Add test case to verify 400 error when bookingFieldsResponses contains null values
- Create ValidateBookingFieldsResponses decorator to reject null values in booking field responses
- Apply validator to CreateBookingInput_2024_08_13.bookingFieldsResponses property
- Ensure all booking field response values are non-null strings
* feat: transform null values to empty strings in bookingFieldsResponses
- Remove ValidateBookingFieldsResponses validator that rejected null values
- Add Transform decorator to convert null values to empty strings in bookingFieldsResponses
- Update test to verify null values are transformed to empty strings instead of returning 400 error
* remove extra spaces
* test: add rescheduleReason null value test case
---------
Co-authored-by: Morgan <33722304+ThyMinimalDev@users.noreply.github.com>