Create IFoodService.cs

[iamcymentho]

Description:

I Introduced the IFoodService interface to establish a clear contract for the FoodService class. This allows for better code organization, adherence to the Dependency Inversion Principle, and facilitates unit testing. The interface defines the GetAllFoods method, enhancing the modularity and maintainability of the codebase.

• This commit is a prerequisite for separating concerns and achieving a more structured and testable service layer.