Added lots of commands

Simplified KeePass client

ModernKeePass.Application/Group/Commands/DeleteGroup/DeleteGroupCommand.cs

@@ -0,0 +1,35 @@
+using System.Threading.Tasks;
+using MediatR;
+using ModernKeePass.Application.Common.Interfaces;
+using ModernKeePass.Application.Database.Queries.IsDatabaseOpen;
+using ModernKeePass.Application.Group.Models;
+using ModernKeePass.Domain.Exceptions;
+
+namespace ModernKeePass.Application.Group.Commands.DeleteGroup
+{
+    public class DeleteGroupCommand : IRequest
+    {
+        public GroupVm Group { get; set; }
+
+        public class DeleteGroupCommandHandler : IAsyncRequestHandler<DeleteGroupCommand>
+        {
+            private readonly IDatabaseProxy _database;
+            private readonly IMediator _mediator;
+
+            public DeleteGroupCommandHandler(IDatabaseProxy database, IMediator mediator)
+            {
+                _database = database;
+                _mediator = mediator;
+            }
+
+            public async Task Handle(DeleteGroupCommand message)
+            {
+                var isDatabaseOpen = await _mediator.Send(new IsDatabaseOpenQuery());
+                if (!isDatabaseOpen) throw new DatabaseClosedException();
+
+                await _database.DeleteGroup(message.Group.Id);
+                message.Group = null;
+            }
+        }
+    }
+}