Refactor attachment handling in email fetching

Consolidate `WithAttachments` behavior into `MailSearchFilter` to simplify the API and reduce redundancy.

- Removed `withAttachments` parameter from `FetchEmailsAsync` in `IImapEmailService`.
- Added `WithAttachments` property to `MailSearchFilter` to control attachment inclusion.
- Removed `WithAttachments` property from `FetchEmailsQuery` as it is now encapsulated in `MailSearchFilter`.
- Updated `FetchEmailsQueryHandler` to use `MailSearchFilter` for attachment handling.
- Refactored `LimilabsImapEmailService` to use `MailSearchFilter.WithAttachments` for mapping email data.

These changes improve maintainability and clarity by centralizing attachment-related options in `MailSearchFilter`.

src/infrastructure/DigitalData.MessagingService.Infrastructure/Services/LimilabsImapEmailService.cs

@@ -27,7 +27,6 @@ public class LimilabsImapEmailService(
     public async Task<IEnumerable<ReceivedEmailContext>> FetchEmailsAsync(
         EmailAccountDto account,
         MailSearchFilter filter,
-        bool withAttachments = false,
         CancellationToken cancellationToken = default)
     {
         using var imap = new Imap();
@@ -104,7 +103,7 @@ public class LimilabsImapEmailService(
                     if (filter.HasAttachments && mail.Attachments.Count == 0 && mail.Visuals.Count == 0)
                         continue;
 
-                    results.Add(MapToContext(uid, mail, flags, withAttachments));
+                    results.Add(MapToContext(uid, mail, flags, filter.WithAttachments));
                 }
                 catch (Exception ex)
                 {