[TFM Display] Add feature flag to display TFM. (#8867)

* Add display tfm feature flag.

* nit.

Author: Daniel Jacinto

src/AccountDeleter/EmptyFeatureFlagService.cs

@@ -81,6 +81,11 @@ public bool IsDisplayPackagePageV2PreviewEnabled(User user)
             throw new NotImplementedException();
         }
 
+        public bool IsDisplayTargetFrameworkEnabled()
+        {
+            throw new NotImplementedException();
+        }
+
         public bool IsDisplayVulnerabilitiesEnabled()
         {
             throw new NotImplementedException();

src/GitHubVulnerabilities2Db/Fakes/FakeFeatureFlagService.cs

@@ -269,5 +269,10 @@ public bool IsDisplayPackagePageV2PreviewEnabled(User user)
         {
             throw new NotImplementedException();
         }
+
+        public bool IsDisplayTargetFrameworkEnabled()
+        {
+            throw new NotImplementedException();
+        }
     }
 }

src/NuGetGallery.Services/Configuration/FeatureFlagService.cs

@@ -52,6 +52,7 @@ public class FeatureFlagService : IFeatureFlagService
         private const string DisplayPackagePageV2PreviewFeatureName = GalleryPrefix + "DisplayPackagePageV2Preview";
         private const string DisplayPackagePageV2FeatureName = GalleryPrefix + "DisplayPackagePageV2";
         private const string ShowReportAbuseSafetyChanges = GalleryPrefix + "ShowReportAbuseSafetyChanges";
+        private const string DisplayTargetFrameworkFeatureName = GalleryPrefix + "DisplayTargetFramework";
 
         private const string ODataV1GetAllNonHijackedFeatureName = GalleryPrefix + "ODataV1GetAllNonHijacked";
         private const string ODataV1GetAllCountNonHijackedFeatureName = GalleryPrefix + "ODataV1GetAllCountNonHijacked";
@@ -356,5 +357,10 @@ public bool IsDisplayBannerEnabled()
         {
             return _client.IsEnabled(DisplayBannerFlightName, defaultValue: false);
         }
+
+        public bool IsDisplayTargetFrameworkEnabled()
+        {
+            return _client.IsEnabled(DisplayTargetFrameworkFeatureName, defaultValue: false);
+        }
     }
 }

src/NuGetGallery.Services/Configuration/IFeatureFlagService.cs

@@ -286,5 +286,10 @@ public interface IFeatureFlagService
         /// Whether or not display the banner on nuget.org
         /// </summary>
         bool IsDisplayBannerEnabled();
+        
+        /// <summary>
+        /// Whether or not display target framework badges and table on nuget.org
+        /// </summary>
+        bool IsDisplayTargetFrameworkEnabled();
     }
 }

src/NuGetGallery/App_Data/Files/Content/flags.json

@@ -30,7 +30,8 @@
     "NuGetGallery.EmbeddedIcons": "Enabled",
     "NuGetGallery.MarkdigMdRendering": "Enabled",
     "NuGetGallery.ImageAllowlist": "Enabled",
-    "NuGetGallery.ShowReportAbuseSafetyChanges": "Enabled"
+    "NuGetGallery.ShowReportAbuseSafetyChanges": "Enabled",
+    "NuGetGallery.DisplayTFM": "Enabled"
   },
   "Flights": {
     "NuGetGallery.TyposquattingFlight": {

src/VerifyMicrosoftPackage/Fakes/FakeFeatureFlagService.cs

@@ -119,5 +119,7 @@ public bool IsDisplayPackagePageV2PreviewEnabled(User user)
         {
             throw new NotImplementedException();
         }
+
+        public bool IsDisplayTargetFrameworkEnabled() => throw new NotImplementedException();
     }
 }