Maua client improvements

1-Fix index indentation.
2-Move 'buy now' button next to user profile.
3-*Refactor 'don't know answer' service.
4- Apply refactor on question and custom practice ctrl.

* This method had a youtube API call inside, but we don't have to make the user wait for all the information while the video gets the info from
that youtube API. So this methods were divided increasing speed of the main info response.