Add JsonFormatProperty snippet and use it

Co-authored-by: jorgerangel-msft <102122018+jorgerangel-msft@users.noreply.github.com>

Author: Copilot

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/src/Providers/MrwSerializationTypeDefinition.Dynamic.cs

@@ -531,7 +531,7 @@ private MethodProvider BuildTryResolveArrayMethod(PropertyProvider property)
             var dataDeclStatement = Declare("data", typeof(BinaryData),
                 Static(typeof(ModelReaderWriter)).Invoke(nameof(ModelReaderWriter.Write), [
                     new InvokeMethodExpression(null, $"Active{property.Name}", []),
-                    Static(typeof(ModelReaderWriterOptions)).Property(nameof(ModelReaderWriterOptions.Json)),
+                    ModelReaderWriterOptionsSnippets.JsonFormatProperty,
                     ModelReaderWriterContextSnippets.Default
                 ]),
                 out var dataVar);

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/src/Snippets/ModelReaderWriterOptionsSnippets.cs

@@ -15,6 +15,7 @@ internal static class ModelReaderWriterOptionsSnippets
         internal static ScopedApi<string> WireFormat => Literal("W");
         internal static ScopedApi<string> JsonFormat => Literal("J");
         internal static ScopedApi<string> XmlFormat => Literal("X");
+        internal static ScopedApi<ModelReaderWriterOptions> JsonFormatProperty => Static(typeof(ModelReaderWriterOptions)).Property(nameof(ModelReaderWriterOptions.Json)).As<ModelReaderWriterOptions>();
         internal static ScopedApi<ModelReaderWriterOptions> InitializeWireOptions => New.Instance(typeof(ModelReaderWriterOptions), Wire).As<ModelReaderWriterOptions>();
     }
 }