Establish a CacheProfile topic view model, if needed

It shouldn't be necessary to access the `CacheProfile` topic via views since the cache profile attributes are set via the new `[TopicResponseCache]`. However, should it be necessary (e.g., to update the meta headers), the `CacheProfileTopicViewModel` allows one to be returned to the client.

This isn't (currently) exposed via e.g. the `PageTopicViewModel` since it's not _expected_ to be needed, and we don't want to add potential overhead to _every_ page mapping.

Author: JeremyCaney

OnTopic.ViewModels/_items/CacheProfileTopicViewModel.cs

@@ -0,0 +1,68 @@
+/*==============================================================================================================================
+| Author        Ignia, LLC
+| Client        Ignia, LLC
+| Project       Topics Library
+\=============================================================================================================================*/
+
+namespace OnTopic.ViewModels {
+
+  /*============================================================================================================================
+  | VIEW MODEL: CACHE PROFILE
+  \---------------------------------------------------------------------------------------------------------------------------*/
+  /// <summary>
+  ///   Provides a strongly-typed model for feeding views with information about a <c>CacheProfile</c> topic, as referenced by
+  ///   the <see cref="PageTopicViewModel"/> and its derivatives.
+  /// </summary>
+  /// <remarks>
+  ///   Typically, view models should be created as part of the presentation layer. The <see cref="Models"/> namespace contains
+  ///   default implementations that can be used directly, used as base classes, or overwritten at the presentation level. They
+  ///   are supplied for convenience to model factory default settings for out-of-the-box content types.
+  /// </remarks>
+  public record CacheProfileTopicViewModel: ItemTopicViewModel {
+
+    /*==========================================================================================================================
+    | DURATION
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Gets or sets the duration in seconds for which the response is cached. If this property is set, the "max-age" in the
+    ///   "Cache-control" header is set in the response.
+    /// </summary>
+    public int? Duration { get; init; }
+
+    /*==========================================================================================================================
+    | LOCATION
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Gets or sets the location where the data from a particular URL must be cached. If this property is set, the
+    ///   "Cache-control" header is set in the response.
+    /// </summary>
+    public string? Location { get; init; }
+
+    /*==========================================================================================================================
+    | NO STORE
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Gets or sets the value which determines whether the data should be stored or not. When set to true, it sets the
+    ///   "Cache-control" header in the response to "no-store". Ignores the "Location" parameter for values other than "None".
+    ///   Ignores the "Duration" parameter.
+    /// </summary>
+    public bool? NoStore { get; init; }
+
+    /*==========================================================================================================================
+    | VARY BY HEADER
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Gets or sets which header the cache should vary by, if appropriate.
+    /// </summary>
+    public string? VaryByHeader { get; init; }
+
+    /*==========================================================================================================================
+    | VARY BY QUERY KEYS
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Gets or sets which query string parameter keys the cache should vary by, if appropriate. Should be comma delimited.
+    /// </summary>
+    public string? VaryByQueryKeys { get; init; }
+
+  } //Class
+} //Namespace