Changed EmailTemplateDto properties from init-only to mutable (get/set), removed 'required' from Name, and added a new LangCode property with a default value. Also updated using directives and added conditional compilation in EmailTemplate.cs for .NET Framework compatibility. No functional changes to EmailTemplate class.
Replaced ReadEmailTemplateResponse with EmailTemplateDto as the standard DTO for email templates. Updated ReadEmailTemplateQuery and its handler to use EmailTemplateDto. Removed the obsolete MappingProfile and cleaned up EmailTemplateDto with improved documentation. Simplified UpdateEmailTemplateCommandHandler by removing conditional updates for Body and Subject. These changes streamline DTO usage and reduce redundancy in email template handling.
Removed ApiExplorerSettings attribute. Changed Body and Subject to nullable strings with init accessors and updated their documentation. Added AddedWhen and ChangedWhen timestamp properties to track template creation and modification dates. Cleaned up property formatting.
