Removed unnecessary using directives in `UpdateEmailTemplateCommandHandler.cs`. Added a new `BadRequestException` class in `BadRequestException.cs` to handle bad request scenarios with customizable error messages.
- Updated namespace for `ResetEmailTemplateCommand` and added a constructor for flexible initialization.
- Introduced `ChangedWhen` property in `UpdateEmailTemplateCommand` to track modification time.
- Refactored `UpdateEmailTemplateCommandHandler` for improved email template retrieval logic.
- Modified `EmailTemplateController` method signatures and logic for clarity and consistency.
- Added `EmailTemplate` entry in `appsettings.json` for database trigger configuration.
- Added XML documentation to the `Handle` method in `UpdateEmailTemplateCommandHandler`.
- Improved readability in `ReadEmailTemplateQueryHandler` by storing the mapped response in a variable.
- Updated properties in `ReadEmailTemplateResponse` to be mutable and renamed `Type` to `Name` with a type change from `int` to `string`.
- Added data annotations in `EmailTemplate` for `AddedWhen` and introduced a new nullable `ChangedWhen` property.
- Included necessary using directives for data annotations in `EmailTemplate.cs`.
- Updated EmailTemplateDto to allow mutable Body and Subject properties.
- Implemented IRequest interface in UpdateEmailTemplateCommand for MediatR.
- Enhanced error handling in EmailTemplateController with NotFoundException.
- Introduced UpdateEmailTemplateCommandHandler for processing update commands.
- Added NotFoundException class for improved error handling.
