Variants should also be treated like random questions in the sense that
a summary row
should be displayed for them as well.
This commit deals with handling variants.
Also the name of the calculated_random_question_summary class has
changed to
calculated_question_summary to be more generic as the summary row is not
specific to random questions only.
Also removed the protected function too_many_subq_and_or_variant_rows
and the const SUBQ_AND_VARIANT_ROW_LIMIT as they were not being used
anymore.
Part of MDL-62610
Fixed calculated_random_question_summary:get_min_max_of and calculated_random_question_summary:get_min_max_of_sd
functions and added unit tests
Part of MDL-62610
Modified calculated_random_question_summary class so that it can return minimum and maximum
of each attribute of the sub questions it is summarising.
Part of MDL-62610
quiz_question_statistics_stats renamed to question_statistics_calculator
separate class question_statistics used to store calculated stats
and api changed, also code generally cleaned up.
quiz_question_statistics_stats renamed to question_statistics_calculator
separate class question_statistics used to store calculated stats
and api changed, also code generally cleaned up.