[ADD] Simple views for accounts and channels

Manager.Data/Contexts/LibraryDbContext.cs

@@ -58,6 +58,9 @@ public sealed class LibraryDbContext : DbContext
                 .WithOne(x => x.Channel)
                 .HasForeignKey<ClientAccountEntity>(e => e.Id)
                 .IsRequired(false);
+            channel.HasMany(x => x.Files)
+                .WithOne()
+                .HasForeignKey(f => f.ForeignKey);
         });
 
         modelBuilder.Entity<ClientAccountEntity>(cae =>
@@ -71,6 +74,9 @@ public sealed class LibraryDbContext : DbContext
                 .WithOne(ca => ca.ClientAccount)
                 .HasForeignKey<ChannelEntity>(ce => ce.Id)
                 .IsRequired(false);
+            cae.HasMany(x => x.Files)
+                .WithOne()
+                .HasForeignKey(f => f.ForeignKey);
         });
 
         modelBuilder.Entity<HttpCookieEntity>(httpce =>