Added GetAvailableTimeslotsQuery, GetAvailableTimeslotsQueryInput, and GetAvailableTimeslotsQueryOutput
to handle fetching available timeslots for a shop, improving the structure and separation of concerns.
This commit introduces new actions for adding, removing, and emptying items in the basket, along with their corresponding input classes. It also updates the BasketController to utilize these new actions, enhancing the basket management functionality.
