feat(Question Stash and Session Manager): Add question stash and fetch strategy, added a Session Manager.

[fingerson]

• Created QuestionStash Singleton Class

• • Public methods:
• • public func isRepeatedQuestion(question: String) -> Bool
• • public func addQuestion(question: String, answerStatus: Bool = true)
• • Stash stores the last 5000 answered questions.

• Removed AnswerTracker class (incorporated into SessionManager).

• Added SessionManager Singleton Class:

• • Public methods:
• • func startSession(
    category: Manager.API.QuestionCategory,
    difficulty: Manager.API.Difficulty,
    answerType: Manager.API.AnswerTypes,
    amount: Int = 10
    ) async throws -> Bool
• • func sessionEnded() -> Bool
• • func currentQuestion() throws -> Question
• • func addResult(answerStatus: Bool) throws

• Modified API to include new methods:

• • fetchQuestions renamed to simpleFetch
• • added new method fetchQuestions which checks if a question is repeated and repeats the API call until the asked number of questions is obtained without repetition.

• Modified QuestionView and InitialView to work with session manager.

• InitialView had data inside the view, passed it to ViewModel.

• Bug identified on both this branch and dev: Switching to the profile tab and then back to the quiz tab during a quiz session will cause weird behaviors. Added to issues.

Closes #11 ans #9