Quiz mode: big picture

[VladimirKhil]

• refactor SICore so Common Stakes Question logic does not depend on Final round type
• implement Common Question type: everybody answers the question and the the showman checks their answers
• simplify answers validation: SIGame: do not ask showman to validate similar answer multiple times in final round #182
• optionally allow showman to validate player answers on the fly (there should be UI with all recevied answers and Yes/No buttons)
• optionally support round type in which answers for questions are shown after the end of the theme play (questions are played sequentially) SImulator: quizzes integration #133