Finish Owner Relationship, update races and add first helpers for derived values. Update naming

Stars Assistant/ViewModels/PlanetViewModel.cs

@@ -1,4 +1,5 @@
 using System.Collections.ObjectModel;
+using Microsoft.EntityFrameworkCore;
 using StarsAssistant.Model;
 
 namespace StarsAssistant.ViewModels;
@@ -8,7 +9,7 @@ public partial class PlanetViewModel(Planet planet) : ViewModelBase
     public static ObservableCollection<PlanetViewModel> LoadAll() {
         var context = new StarsDatabase("stars.sqlite");
         var result = new ObservableCollection<PlanetViewModel>();
-        foreach (Planet planet in context.Planets.ToList())
+        foreach (Planet planet in context.Planet.Where(p => p.OwnerId == "Atlantis").ToList())
         {
             var vm = new PlanetViewModel(planet);
             result.Add(vm);
@@ -20,7 +21,7 @@ public partial class PlanetViewModel(Planet planet) : ViewModelBase
 
     public string Name => planet.Name;
 
-    public string Owner => planet.Owner ?? String.Empty;
+    public string Owner => planet.OwnerId ?? String.Empty;
 
     public int Value => planet.Value ?? 0;
 }