refactor: replace local dal abstractions with hrynco-ef packages

Remove duplicate IEntity, Entity, ITransaction, IUnitOfWork, EfRepository,
EfUnitOfWork, EfTransactionAdapter — now consumed from HrynCo.DAL.Abstract
and HrynCo.DAL.EF packages (1.0.1).

Ref: IT-0

HrynCo.NotificationService.DAL.Abstract/Providers/EmailChannelUsage.cs

@@ -1,4 +1,4 @@
-using HrynCo.NotificationService.DAL.Abstract.Entities;
+using HrynCo.DAL.Abstract.Entities;
 
 namespace HrynCo.NotificationService.DAL.Abstract.Providers;