feat: DTOs and interfaces

Services/Interfaces/IMissionCategoryService.cs

@@ -0,0 +1,13 @@
+using GamificationService.Models.Database;
+
+namespace GamificationService.Services.Interfaces;
+
+public interface IMissionCategoryService
+{
+    Task<MissionCategory?> GetCategoryByIdAsync(Guid categoryId);
+    Task<MissionCategory?> GetCategoryByTitleAsync(string title);
+    Task<IEnumerable<MissionCategory>> GetAllCategoriesAsync();
+    Task<MissionCategory> CreateCategoryAsync(MissionCategory category);
+    Task<MissionCategory> UpdateCategoryAsync(MissionCategory category);
+    Task<bool> DeleteCategoryAsync(Guid categoryId);
+}