TF-1933 Add GetStoredSendingEmail interactor

(cherry picked from commit bcf27cbaa5fbc62767a82e658e543339c5197991)

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

@@ -219,4 +219,9 @@ class EmailDataSourceImpl extends EmailDataSource {
   Future<List<SendingEmail>> deleteMultipleSendingEmail(AccountId accountId, UserName userName, List<String> sendingIds) {
     throw UnimplementedError();
   }
+
+  @override
+  Future<SendingEmail> getStoredSendingEmail(AccountId accountId, UserName userName, String sendingId) {
+    throw UnimplementedError();
+  }
 }

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

@@ -279,4 +279,12 @@ class EmailHiveCacheDataSourceImpl extends EmailDataSource {
       return await _sendingEmailCacheManager.deleteMultipleSendingEmail(accountId, userName, sendingIds);
     }).catchError(_exceptionThrower.throwException);
   }
+
+  @override
+  Future<SendingEmail> getStoredSendingEmail(AccountId accountId, UserName userName, String sendingId) {
+    return Future.sync(() async {
+      final sendingEmailCache = await _sendingEmailCacheManager.getStoredSendingEmail(accountId, userName, sendingId);
+      return sendingEmailCache.toSendingEmail();
+    }).catchError(_exceptionThrower.throwException);
+  }
 }