[💡 Feature]: Make the auto dismiss timer configurable

[mikaoelitiana]

Currently, the auto dismiss of ticket scan redeem result is set to 15 seconds

pretixscan-ios/pretixSCAN/Ticket Scanning/TicketStatus/TicketStatusController.swift

Lines 50 to 57 in 61e0ba8

	@objc func setupAutoDismiss() {
	timer?.invalidate()
	print("starting count down")
	let delay = 15.0 // seconds
	let dismissTimer = Timer(timeInterval: delay, target: self, selector: #selector(dismissVC), userInfo: nil, repeats: false)
	RunLoop.main.add(dismissTimer, forMode: .common)
	timer = dismissTimer
	}

It would be great if the delay value could be changed from the app settings in order to decrease it. On big events with people queuing at the entrance, it can be beneficial to reduce that delay to 2 or 3 seconds.

An additional idea is to also disable auto dismissal when the ticket scan has an error. Currently it is only disabled when ticket status is incomplete :

pretixscan-ios/pretixSCAN/Ticket Scanning/TicketStatus/RedeemTicketViewModel.swift

Lines 85 to 91 in 61e0ba8

	if let redemptionResponse, redemptionResponse.status == .incomplete {
	// we need to ask questions
	stopCountDown()
	updateQuestionsAndAnswers(redemptionResponse)
	showQuestions()
	} else {
	announceResult(redemptionResponse, nil)