Add runtime mode (BackofficeDevelopment, Development and Production) (#12631)

* Add runtime mode setting

* Only enable Razor runtime compilation in development modes

* Only enable ModelsBuilder generation in development modes

* Fix disabling ModelsBuilder controllers

* Add IRuntimeModeValidationService and IRuntimeModeValidator

* Add JITOptimizerValidator

* Add UmbracoApplicationUrlValidator

* Add UseHttpsValidator

* Add RuntimeMinificationValidator

* Add ModelsBuilderModeValidator

* Remove .NET 6 preview 1 fix for Razor runtime compilation

* Only allow InMemoryAuto in backoffice development mode

* Make runtime mode validators public, so they can be easily removed if required

* Add comment to highlight removing RazorCompileOnBuild, RazorCompileOnPublish and CopyRazorGenerateFilesToPublishDirectory when using ModelsMode InMemoryAuto

* Add documentation

* Update src/Umbraco.Web.Common/ModelsBuilder/NoopModelsBuilderDashboardProvider.cs

Co-authored-by: Ronald Barendse <ronald@barend.se>

Co-authored-by: Nikolaj Geisle <70372949+Zeegaan@users.noreply.github.com>

src/Umbraco.Core/Configuration/Models/RuntimeSettings.cs

@@ -1,16 +1,24 @@
 // Copyright (c) Umbraco.
 // See LICENSE for more details.
 
+using System.ComponentModel;
+
 namespace Umbraco.Cms.Core.Configuration.Models;
 
 /// <summary>
-///     Typed configuration options for runtime settings.
+/// Typed configuration options for runtime settings.
 /// </summary>
 [UmbracoOptions(Constants.Configuration.ConfigRuntime)]
 public class RuntimeSettings
 {
     /// <summary>
-    ///     Gets or sets a value for the maximum query string length.
+    /// Gets or sets the runtime mode.
+    /// </summary>
+    [DefaultValue(RuntimeMode.BackofficeDevelopment)]
+    public RuntimeMode Mode { get; set; } = RuntimeMode.BackofficeDevelopment;
+
+    /// <summary>
+    /// Gets or sets a value for the maximum query string length.
     /// </summary>
     public int? MaxQueryStringLength { get; set; }