Update namespaces to Common.Dto for DTO-related files

Refactored PlaceholderExtensions, DtoMappingProfile, and InvokeActionTests
to use the ReC.Application.Common.Dto namespace instead of
ReC.Application.Common.Behaviors.Action. Updated using directives and
namespaces to improve code organization for DTO-related logic.

src/ReC.Application/Common/Dto/DtoMappingProfile.cs

@@ -1,4 +1,3 @@
-using ReC.Application.Common.Behaviors.Action;
 using ReC.Domain.Views;
 
 namespace ReC.Application.Common.Dto;

src/ReC.Application/Common/Dto/PlaceholderExtensions.cs

@@ -3,7 +3,7 @@ using System.Reflection;
 using System.Text.RegularExpressions;
 using ReC.Application.Common.Exceptions;
 
-namespace ReC.Application.Common.Behaviors.Action;
+namespace ReC.Application.Common.Dto;
 
 public static partial class PlaceholderExtensions
 {

tests/ReC.Tests/Application/Behaviors/InvokeActionTests.cs

@@ -1,5 +1,5 @@
 using System.ComponentModel.DataAnnotations.Schema;
-using ReC.Application.Common.Behaviors.Action;
+using ReC.Application.Common.Dto;
 using ReC.Application.Common.Exceptions;
 
 namespace ReC.Tests.Application.Behaviors;