Fix answers not saved for subject based exam bug
Fix answers not saved for subject based exam bug

- For subject based exam API will send questions mixed, so in app questions
will be grouped based on subjects.
- Issue is we will pass attempts items to question view controller before grouping. So when user selects an answer
and submits it, some other answer will get saved.
- This is fixed by grouping attempt items before displaying it

testpress/ios-app,testpress/ios-app,testpress/ios-app,testpress/ios-app