Most services are implemented as command/queries

Code cleanup

ModernKeePass.Application/Cryptography/Queries/GetKeyDerivations/GetKeyDerivationsQuery.cs

@@ -0,0 +1,28 @@
+using System.Collections.Generic;
+using AutoMapper;
+using MediatR;
+using ModernKeePass.Application.Common.Interfaces;
+using ModernKeePass.Application.Cryptography.Models;
+
+namespace ModernKeePass.Application.Cryptography.Queries.GetKeyDerivations
+{
+    public class GetKeyDerivationsQuery : IRequest<IEnumerable<KeyDerivationVm>>
+    {
+        public class GetKeyDerivationsQueryHandler : IRequestHandler<GetKeyDerivationsQuery, IEnumerable<KeyDerivationVm>>
+        {
+            private readonly ICryptographyClient _cryptography;
+            private readonly IMapper _mapper;
+
+            public GetKeyDerivationsQueryHandler(ICryptographyClient cryptography, IMapper mapper)
+            {
+                _cryptography = cryptography;
+                _mapper = mapper;
+            }
+
+            public IEnumerable<KeyDerivationVm> Handle(GetKeyDerivationsQuery message)
+            {
+                yield return _mapper.Map<KeyDerivationVm>(_cryptography.KeyDerivations);
+            }
+        }
+    }
+}