TF-1923 Fix logic get stored email when offline

(cherry picked from commit fa74abdf2663e80e445236449c5aec3e5c9267e5)

lib/features/email/data/datasource/email_datasource.dart

@@ -82,7 +82,7 @@ abstract class EmailDataSource {
 
   Future<void> storeEmail(Session session, AccountId accountId, Email email);
 
-  Future<Email?> getEmailStored(Session session, AccountId accountId, EmailId emailId);
+  Future<Email> getStoredEmail(Session session, AccountId accountId, EmailId emailId);
 
   Future<void> storeOpenedEmail(Session session, AccountId accountId, DetailedEmail detailedEmail);
 

lib/features/email/data/datasource_impl/email_datasource_impl.dart

@@ -185,7 +185,7 @@ class EmailDataSourceImpl extends EmailDataSource {
   }
 
   @override
-  Future<Email?> getEmailStored(Session session, AccountId accountId, EmailId emailId) {
+  Future<Email> getStoredEmail(Session session, AccountId accountId, EmailId emailId) {
     throw UnimplementedError();
   }
 

lib/features/email/data/datasource_impl/email_hive_cache_datasource_impl.dart

@@ -229,11 +229,10 @@ class EmailHiveCacheDataSourceImpl extends EmailDataSource {
   }
 
   @override
-  Future<Email?> getEmailStored(Session session, AccountId accountId, EmailId emailId) {
+  Future<Email> getStoredEmail(Session session, AccountId accountId, EmailId emailId) {
     return Future.sync(() async {
-      final email = await _emailCacheManager.getEmailFromCache(accountId, session.username, emailId);
-      log('EmailHiveCacheDataSourceImpl::getEmailFromCache():emailId: $email');
-      return email?.toEmail();
+      final email = await _emailCacheManager.getStoredEmail(accountId, session.username, emailId);
+      return email.toEmail();
     }).catchError(_exceptionThrower.throwException);
   }
 

lib/features/email/data/repository/email_repository_impl.dart

@@ -210,8 +210,8 @@ class EmailRepositoryImpl extends EmailRepository {
   }
 
   @override
-  Future<Email?> getEmailStored(Session session, AccountId accountId, EmailId emailId) {
-    return emailDataSource[DataSourceType.hiveCache]!.getEmailStored(session, accountId, emailId);
+  Future<Email> getStoredEmail(Session session, AccountId accountId, EmailId emailId) {
+    return emailDataSource[DataSourceType.hiveCache]!.getStoredEmail(session, accountId, emailId);
   }
 
   @override