TF-185 [BUG] Fix can not display all parts of email which have multiple html part

lib/features/email/domain/repository/email_repository.dart

@@ -35,5 +35,5 @@ abstract class EmailRepository {
     MarkStarAction markStarAction
   );
 
-  Future<String> transformEmailContentToHtml(EmailContent emailContent);
+  Future<List<EmailContent>> transformEmailContent(List<EmailContent> emailContents);
 }

lib/features/email/domain/state/get_email_content_state.dart

@@ -2,13 +2,13 @@ import 'package:core/core.dart';
 import 'package:model/model.dart';
 
 class GetEmailContentSuccess extends UIState {
-  final EmailContent emailContent;
+  final List<EmailContent> emailContents;
   final List<Attachment> attachments;
 
-  GetEmailContentSuccess(this.emailContent, this.attachments);
+  GetEmailContentSuccess(this.emailContents, this.attachments);
 
   @override
-  List<Object?> get props => [emailContent, attachments];
+  List<Object?> get props => [emailContents, attachments];
 }
 
 class GetEmailContentFailure extends FeatureFailure {

lib/features/email/domain/usecases/get_email_content_interactor.dart

@@ -17,15 +17,8 @@ class GetEmailContentInteractor {
       final email = await emailRepository.getEmailContent(accountId, emailId);
 
       if (email.emailContentList.isNotEmpty) {
-        final emailContent = email.emailContentList.first;
-        if (emailContent.type == EmailContentType.textHtml) {
-          final contentHtml = await emailRepository.transformEmailContentToHtml(emailContent);
-          yield Right<Failure, Success>(GetEmailContentSuccess(
-            EmailContent(emailContent.type, contentHtml),
-            email.allAttachments));
-        } else {
-          yield Right<Failure, Success>(GetEmailContentSuccess(emailContent, email.allAttachments));
-        }
+        final newEmailContents = await emailRepository.transformEmailContent(email.emailContentList);
+        yield Right<Failure, Success>(GetEmailContentSuccess(newEmailContents, email.allAttachments));
       } else {
         yield Left(GetEmailContentFailure(null));
       }