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.Abstract/Entities/Entity.cs

@@ -0,0 +1,25 @@
+namespace HrynCo.DAL.Abstract.Entities;
+
+[Serializable]
+public abstract class Entity<TId> : IEntity<TId> where TId : struct
+{
+    public TId Id { get; set; }
+    public DateTimeOffset Created { get; set; }
+    public DateTimeOffset? Updated { get; set; }
+}
+
+[Serializable]
+public abstract class Entity : Entity<Guid>
+{
+    protected Entity()
+    {
+        Id = Guid.NewGuid();
+        Created = DateTimeOffset.UtcNow;
+    }
+
+    protected Entity(Guid id)
+    {
+        Id = id;
+        Created = DateTimeOffset.UtcNow;
+    }
+}

HrynCo.DAL.Abstract/Entities/IEntity.cs

@@ -0,0 +1,8 @@
+namespace HrynCo.DAL.Abstract.Entities;
+
+public interface IEntity<TId> where TId : struct
+{
+    TId Id { get; set; }
+    DateTimeOffset Created { get; set; }
+    DateTimeOffset? Updated { get; set; }
+}