Add helpful string overrides

src/core/Elsa.Abstractions/ActivityProviders/RuntimeActivityInstance.cs

@@ -31,5 +31,7 @@
         /// A value indicating whether the workflow context (if any) will be persisted automatically after executing this activity. 
         /// </summary>
         public bool SaveWorkflowContext { get; set; }
+        
+        public override string ToString() => $"{ActivityType.Type} - {Id}";
     }
 }

src/core/Elsa.Abstractions/Models/ActivityInstance.cs

@@ -20,5 +20,7 @@ namespace Elsa.Models
         public string Type { get; set; } = default!;
         public JObject Data { get; set; } = new();
         public object? Output { get; set; }
+
+        public override string ToString() => $"{Type} - {Id}";
     }
 }

src/core/Elsa.Abstractions/Services/Models/ActivityBlueprint.cs

@@ -31,5 +31,7 @@
         public bool PersistWorkflow { get; set; }
         public bool LoadWorkflowContext { get; set; }
         public bool SaveWorkflowContext { get; set; }
+
+        public override string ToString() => Type;
     }
 }