Avoid NREs in MVC sample

- see e.g. results of `GET ~/Home/Post`
- use parentheses to avoid `?` confusing Razor

nit: remove unused Home/Test.cshtml view

samples/MvcSample.Web/Views/Home/Create.cshtml

@@ -26,7 +26,7 @@
         if (metadata != null)
         {
             var typeName = metadata.ModelType.Name;
-            var description = metadata.Description;
+            var description = metadata.Description ?? "no description";
             <p>@typeName has description '@description' and contains</p>
             <ul>
                 @foreach (var property in metadata.Properties)

samples/MvcSample.Web/Views/Home/Test.cshtml

@@ -1 +0,0 @@
-Hello From Razor

samples/MvcSample.Web/Views/Shared/HelloWorldPartial.cshtml

@@ -1,6 +1,6 @@
 @using MvcSample.Web.Models
 @model User
 
-<strong>Hello @Model.Name from Partial</strong>
+<strong>Hello @(Model?.Name) from Partial</strong>
 
 <a href="@Url.Action("Create", "Home")">Create Something!</a>

samples/MvcSample.Web/Views/Shared/MyView.cshtml

@@ -53,7 +53,7 @@
     <p><a href="http://asp.net" class="btn btn-primary btn-large">Learn more &raquo;</a></p>
 </div>
 <div class="row">
-    <h3 title="@Model.Name" class="@nullValue">Hello @Html.DisplayTextFor(User => User)! Happy @Model.Age birthday.</h3>
+    <h3 title="@(Model?.Name)" class="@nullValue">Hello @Html.DisplayTextFor(User => User)! Happy @(Model?.Age) birthday.</h3>
     <h3 id="qux">This value was retrieved asynchronously: @(await AsyncValueRetrieval())</h3>
     <h3>Partial Async: @await Html.PartialAsync("HelloWorldPartial", Model)</h3>
     <h3>