Unnecessary capitals in some English language strings

[pkgh]

In compliance with the recent Moodle Product Guidelines recommendations at

https://moodledev.io/general/contentguidelines/styleguide/grammar

I'd like to propose that these English language strings were updated:

$string['questionnaireadministration'] = 'Questionnaire Administration';

=> Questionnaire administration

$string['questionnairecloses'] = 'Questionnaire Closes';

=> Questionnaire closes

$string['questionnaireopens'] = 'Questionnaire Opens';

Questionnaire opens

$string['questionnairereport'] = 'Questionnaire Report';

=> Questionnaire report

I've spotted these four, maybe there are some other needless capitalisations to remove.
For me personally, the "Questionnaire closes" and "Questionnaire opens" are the most important at the moment, since the caps look incompatible in the Calendar, in the Timeline and in the Upcoming events block, when compared to other deadlines.

Thanks.