Implement submit answer method

• Send POST request to submit an answer to the current quiz question
• Provide lobbyId, questionNumber and answerId parameters
• Check that userId is in the joinedPlayers
• Validate the submission by questionStart and questionEnd dates
• Check if the user has already submitted the answer

https://gitlab.pg.innopolis.university/quiz-web-engine/readme/-/blob/main/Quiz%20walkthrough.png