feat(variants): allow in-memory objects

src/Microsoft.FeatureManagement/FeatureManager.cs

@@ -847,10 +847,11 @@ private Variant GetVariantFromVariantDefinition(VariantDefinition variantDefinit
                 variantConfiguration = variantDefinition.ConfigurationValue;
             }
 
-            return new Variant()
+            return new Variant
             {
                 Name = variantDefinition.Name,
-                Configuration = variantConfiguration
+                Configuration = variantConfiguration,
+                ConfigurationObject = variantDefinition.ConfigurationObject,
             };
         }
     }

src/Microsoft.FeatureManagement/Variant.cs

@@ -19,5 +19,11 @@ public class Variant
         /// The configuration of the variant.
         /// </summary>
         public IConfigurationSection Configuration { get; set; }
+
+        /// <summary>
+        /// The configuration of the variant.
+        /// When set, variants should prefer this over <see cref="Configuration"/>.
+        /// </summary>
+        public object ConfigurationObject { get; set; }
     }
 }

src/Microsoft.FeatureManagement/VariantDefinition.cs

@@ -21,6 +21,14 @@ public class VariantDefinition
         /// </summary>
         public IConfigurationSection ConfigurationValue { get; set; }
 
+        /// <summary>
+        /// A configuration object that can be used as an alternative to <see cref="ConfigurationValue"/>.
+        /// Custom <see cref="IFeatureDefinitionProvider"/> implementations can populate this property directly
+        /// instead of constructing an <see cref="IConfiguration"/> instance.
+        /// When set, variants should prefer this over <see cref="ConfigurationValue"/>.
+        /// </summary>
+        public object ConfigurationObject { get; set; }
+
         /// <summary>
         /// Overrides the state of the feature if this variant has been assigned.
         /// </summary>