Added remarks about property serialization

src/Umbraco.Core/Exceptions/DataOperationException.cs

@@ -17,6 +17,9 @@ namespace Umbraco.Core.Exceptions
         /// <value>
         /// The operation.
         /// </value>
+        /// <remarks>
+        /// This object should be serializable to prevent a <see cref="SerializationException" /> to be thrown.
+        /// </remarks>
         public T Operation { get; private set; }
 
         /// <summary>

src/Umbraco.Core/Persistence/EntityNotFoundException.cs

@@ -18,6 +18,9 @@ namespace Umbraco.Core.Persistence
         /// <value>
         /// The identifier.
         /// </value>
+        /// <remarks>
+        /// This object should be serializable to prevent a <see cref="SerializationException" /> to be thrown.
+        /// </remarks>
         public object Id { get; private set; }
 
         /// <summary>

src/Umbraco.Web/Install/InstallException.cs

@@ -24,6 +24,9 @@ namespace Umbraco.Web.Install
         /// <value>
         /// The view model.
         /// </value>
+        /// <remarks>
+        /// This object should be serializable to prevent a <see cref="SerializationException" /> to be thrown.
+        /// </remarks>
         public object ViewModel { get; private set; }
 
         /// <summary>