Support Lesson time limit and password

Testing password In web, create a lesson with password enabled. Open the lesson in the app. Check that the app asks for the password. Check that sending an empty or wrong password shows an error. Check that sending the right password shows the "Start attempt" button or the continue from last page message. Leave the lesson and access it again. Check that it no longer asks for the password (the app remembers it). Check that you can start or continue the lesson. In web, change the password. In the app, perform a PTR in the lesson entry page OR click to start/continue an attempt. Check that the app asks for the password again. Testing timer In web, create a lesson with Time limit , allowing re-takes (it's in the Grade section) and at least 2 pages. Use a low value for the timer (like 1 minute). In the app, start the attempt. Check that you see the timer in the top (the styles are ugly, it will be fixed later when we have the UX design). Without doing anything, leave the lesson player and click "Start attempt" again. Check that the timer continues (it's not restarted to 1 minute). Wait for the timer to reach 0. Check that you're redirected to the end of the lesson. Now start another attempt, change the page and then leave the lesson player. Check that now you see a message saying that you have left during a timed session. Check that clicking  Continue  starts a new attempt (timer is restarted).