Include the url in the stored variation

Author: rmja

src/HttpClient.Cache/Files/FileCache.cs

@@ -258,7 +258,7 @@ TimeProvider timeProvider
             );
             var variationFile = VariationFile.CreateTemp(_tempDirectory);
 
-            await variationFile.WriteAsync(variationKey, variation);
+            await variationFile.WriteAsync(variationKey, request.RequestUri!, variation);
 
             // Let the variation file have the same (possibly updated) expiration as the response
             variationFileName.SetExpiration(variationFile.Info, expiration);

src/HttpClient.Cache/Files/VariationFile.cs

@@ -48,11 +48,12 @@ public readonly bool TryMakePermanent(DirectoryInfo rootDirectory, FileName vari
         };
     }
 
-    public readonly async ValueTask WriteAsync(string key, Variation variation)
+    public readonly async ValueTask WriteAsync(string key, Uri url, Variation variation)
     {
         var model = new VariationModel
         {
             VariationKey = key,
+            Url = url,
             CacheType = variation.CacheType,
             NormalizedVaryHeaders = variation.NormalizedVaryHeaders,
         };

src/HttpClient.Cache/Files/VariationModel.cs

@@ -3,6 +3,7 @@
 internal class VariationModel
 {
     public required string VariationKey { get; init; }
+    public required Uri Url { get; init; }
     public required CacheType CacheType { get; init; }
     public required List<string> NormalizedVaryHeaders { get; init; }
 }