refactor: modernized GenericRepository and UnitOfWork with newer code from Roma

Database/GenericRepository/IGenericRepository.cs

@@ -0,0 +1,24 @@
+using System.Linq.Expressions;
+
+namespace GamificationService.Database.GenericRepository;
+
+public interface IGenericRepository<TEntity> where TEntity : class
+{
+    IQueryable<TEntity> Get(
+        Expression<Func<TEntity, bool>>? filter = null,
+        Func<IQueryable<TEntity>, IOrderedQueryable<TEntity>>? orderBy = null,
+        params Expression<Func<TEntity, object>>[] includes);
+
+    TEntity? GetById(object id);
+    Task<TEntity?> GetByIdAsync(object id);
+
+    void Add(TEntity entity);
+    void AddRange(IEnumerable<TEntity> entities);
+    Task AddAsync(TEntity entity);
+
+    void Delete(object id);
+    void DeleteRange(IEnumerable<TEntity> entities);
+    void Delete(TEntity entity);
+    
+    void Update(TEntity entity);
+}