Updated the `IEmailService` interface and related components to
support multiple recipients in the `SendEmailAsync` method.
- Replaced `Recipient` with `Recipients` in `SendEmailCommand`,
`OutgoingEmailEvent`, and `EmailsController`.
- Updated `SendEmailCommandValidator` to validate a collection
of recipients, ensuring at least one valid email address.
- Modified `LimilabsEmailService` to handle multiple recipients
by iterating over the collection and adding each to the email.
- Adjusted `OutgoingEmailConsumer` to process and log multiple
recipients.
- Updated logging and response structures to reflect the changes.
These changes enable the system to handle emails with multiple
recipients while maintaining proper validation and logging.
Reorganized the solution structure to align with a layered architecture:
- Replaced `src` folder with `core`, `infrastructure`, and `presentation`.
- Moved projects to their respective folders.
- Added `DigitalData.MessagingService.Publisher.Abstraction` project.
- Removed `DigitalData.MessagingService.Client` project.
Updated project configurations and nesting in the solution file.
Added `appsettings.Secrets.json` with RabbitMQ and email account settings:
- RabbitMQ configuration includes hostname, port, credentials, and queue/exchange details.
- Email configuration includes SMTP server details and credentials.
