VSN-2144 : Implementing api call related to departments with their associated cities as a second input of the exportation process.

Merge Request Description

Refactor: Updating Reference Sheet Object DTO

This commit restructures the data transfer object (DTO) for the reference sheet. The goal is to improve clarity and maintain consistency across the codebase, ensuring that the DTO aligns with updated business requirements and supports future scalability.

Feature: API Call Integration

This commit integrates the newly defined API call into the application workflow. It ensures that the system can communicate with the backend service, enabling the retrieval and processing of department and city data as part of the exportation process.

Feature: API Call Implementation

This commit introduces the actual implementation of the API call. It defines the logic required to fetch data from the backend, handle responses, and manage potential errors, thereby completing the functional aspect of the integration.

Feature: Department & Associated Cities DTO

This commit adds a dedicated DTO to represent departments and their associated cities. This structure provides a clear and standardized way to handle hierarchical data, making it easier to manage and consume within the application.

Feature: Defining Endpoint

This commit establishes the backend endpoint required for the new API call. It specifies the route and parameters, ensuring that the frontend can reliably interact with the backend service to fetch the necessary data.

Refactor: Removing Doubled Call

This commit eliminates redundant API calls that were previously executed. By removing duplication, the system achieves better performance, reduces unnecessary load on the backend, and simplifies the overall code logic.

Closes VSN-2144