Validate user

[myanhtruong304]

• Validate user before get user quests list, post quest progres, post claim quest. If userID was not exist in users table, quests would not be generate/get.

- Get user quests list with invalid user_id

- Post user quest progress list with invalid user_id/action

- Post claim quest with invalid user_id/quest_id

[anhnh12]

why need to have 3 cases here?

Suggested change

	//validate quest action
	err_action := e.validateQuestAction(string(log.Action))
	// validate user
	err_user := e.validateUser(log.UserID)
	if err_action != nil && err_user == nil {
	return err_action
	}
	if err_action == nil && err_user != nil {
	return err_user
	}
	if err_action != nil && err_user != nil {
	return errors.New(err_action.Error() + ", " + err_user.Error())
	}
	if err := e.validateQuestAction(string(log.Action)); err != nil {
	return err
	}
	if err := e.validateUser(log.UserID); err != nil {
	return err
	}

[myanhtruong304]

To notify user when they failed to call the API due to invalid fields (action, user_id, quest_id) in their requests, instead of returning null or nothing.

[anhnh12]

same as above

[myanhtruong304]

Same as above, this endpoint will return data: null if user failed to call API.