Questionnaire: make Summary page display more intuitive

[xcaro]

E.g. In this questionnaire, they are 151 questionnaire responses, but 198 question responses. As only complete questionnaire responses are analyzed (the data is exported and cleaned), showing more question responses than questionnaire responses in the summary is confusing.

E.g. here's a view of a recent case:

If we could make the view selectable, this would clean up the summary and make a bit more sense.

• Drop-down: "All responses" [198 in this case]; "Full submissions" [151 in this case]; "Responses not submitted" [47],
• Consistent language to delineate between question-specific responses and full/complete questionnaire submissions.
• Correct the 'total' and percentages on the visual graphs depending on the view.

E.g. here's a view after improvement

[xcaro]

Hi @mchurchward ,

We are from the Open University. Could you please help me to review this PR?

Thanks,

[toanlamt]

Hi @rezeau
I will take responsibility for this issue. I have created a new pull request #589 and rebased it with the MOODLE_401_STABLE branch. Could you please review it again?

Many thanks

[mchurchward]

Closing since it has been replaced with #589