feat: initial solution with HrynCo.DAL.Abstract and HrynCo.DAL.EF

- HrynCo.DAL.Abstract: IEntity<TId>, Entity base classes, ITransaction, IUnitOfWork
- HrynCo.DAL.EF: EfRepository<TDbContext,TEntity>, EfUnitOfWork<TDbContext>, EfTransactionAdapter
- Directory.Packages.props with centralized EF Core 9.0.5 versions
- TeamCity pipeline YAMLs for general-checks and publish

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

HrynCo.DAL.EF/Core/EfRepository.cs

@@ -0,0 +1,46 @@
+using System.Linq.Expressions;
+using Microsoft.EntityFrameworkCore;
+
+namespace HrynCo.DAL.EF.Core;
+
+public abstract class EfRepository<TDbContext, TEntity>
+    where TDbContext : DbContext
+    where TEntity : class
+{
+    protected TDbContext DbContext { get; }
+    protected DbSet<TEntity> DbSet { get; }
+
+    protected EfRepository(TDbContext dbContext)
+    {
+        DbContext = dbContext;
+        DbSet = dbContext.Set<TEntity>();
+    }
+
+    protected async Task AddAsync(TEntity entity, CancellationToken ct = default)
+    {
+        await DbSet.AddAsync(entity, ct);
+    }
+
+    protected async Task AddRangeAsync(IEnumerable<TEntity> entities, CancellationToken ct = default)
+    {
+        await DbSet.AddRangeAsync(entities, ct);
+    }
+
+    protected void Update(TEntity entity)
+    {
+        DbSet.Update(entity);
+    }
+
+    protected void Delete(TEntity entity)
+    {
+        DbSet.Remove(entity);
+    }
+
+    protected void DeleteRange(IEnumerable<TEntity> entities)
+    {
+        DbSet.RemoveRange(entities);
+    }
+
+    protected Task<bool> ExistsAsync(Expression<Func<TEntity, bool>> predicate, CancellationToken ct = default) =>
+        DbSet.AnyAsync(predicate, ct);
+}