It turns out that there are plugins which don't (currently)
clean up their question attempts when a context is deleted.
Therefore, we need to make Moodle core robust to that.
Changes done to fix the warnings thrown in the history view when the
last version of a question is deleted and improved UI to display the
message and a Continue button, to navigate back to the Question bank.
This commit does few things:
* Unify data generators usage to role short name.
* Replace remaining manual steps to use the new data generator.
* Also replaced other manual steps to set config to use data generators.
* Tidy up of some tests, aligning pipes and splitting one line steps into multiple lines.
* Fixes tests to have one Given/When/Then per scenario.
Previously, a set of calculated quiz statistics would only 'last' for
15 minutes. Then they would be considered invalid and not used.
Now, computed statistics are kept indefinitely. Instead, when a new
batch of values are computed for a particular set of settings, older numbers
for the same settings are deleted first. Therefore,
question_stats_cleanup_task is no more.
Previously, when users viewed the question bank, if the quiz statistics
had not already been calculated, we would try to compute them there an then.
This could be very, very slow, leading to session lock problems.
Now, we never try to compute the statistics on the fly. Instead, we rely
on the existing \quiz_statistics\task\recalculate scheduled task to do it.
There is a new method on the column class, for the column to declare any
statistics it requires. The question then efficiently loads all those
statistics in one go, and makes them available as the columns are
rendererd, or do any subsequent processing.
According to Boostrap Popovers documentation for popovers triggered
on focus:
"For proper cross-browser and cross-platform behavior, you must use the
<a> tag, not the <button> tag, and you also must include a tabindex
attribute."
* The object returned by update_question is alwasy a new clone
and the $question passed in will not be modified.
* The returned object has the fields like questionbankentryid and
the ones related to versionning, so it is more like the data
returned by question_bank::load_question_data.
The used the exist in Moodle up to 3.11, but then was removed with
insufficient thought in 4.0 (because we had grander long-term plans
which still have not happened). Until those plans happen, this
commit adds the simple link back on the preview screen.
