fix(messaging): Fix processing successfuly sent messages and remove @mayfail from relevant ui test

Fixes: #7961

src/app_service/service/chat/service.nim

@@ -234,8 +234,11 @@ QtObject:
       if (chat.active):
         self.events.emit(SIGNAL_CHAT_CREATED, CreatedChatArgs(chat: chat))
       
-    for i, msg in messages:
-      self.events.emit(SIGNAL_SENDING_SUCCESS, MessageSendingSuccess(message: msg, chat: chats[i]))
+    for msg in messages:
+      for chat in chats:
+        if chat.id == msg.chatId:
+          self.events.emit(SIGNAL_SENDING_SUCCESS, MessageSendingSuccess(message: msg, chat: chat))
+          break
 
   proc processUpdateForTransaction*(self: Service, messageId: string, response: RpcResponse[JsonNode]) =
     var (chats, messages) = self.processMessageUpdateAfterSend(response)

test/ui-test/testSuites/suite_communities/tst_communityMessageFlows/test.feature

@@ -33,8 +33,6 @@ Feature: Status Desktop community messages
         Then the test image is displayed just before the last message
         And the last chat message contains "Message"
 
-	@mayfail
-	# TODO: The action of sending multiple images doesn't work. It is only sent one.
     Scenario: The user sends multiple test images with a message
         When the user sends multiple test images in the current channel with message "Message" with an image again
         Then the test images are displayed just before the last message