* Pass the section return id to the activity chooser
* Additional behat test to cover the case

David Mudrák authored Jun 19, 2020 and victor committed Jun 22, 2020

The `core\plugininfo\base::is_enabled()` uses three-state logic for its
return value. It can return null as a valid value as per its
documentation. We need to test for the explicit false value in this
case.

To make the attached Behat test able to identify the table, the caption
is added. It seems to be helpful for all users so I leave it displayed
without using the accesshide mechanism.

- provide default styles for links in alerts if the .alert-link
css class is omitted.

Updating default minimal digital age of consent according to current legislation,
that was updated for several countries since 2018.

* Added menuitem role for the "Show x per page" menu.
* Added appropriate aria-labels for the links in the paging bar.

The earlier CONTRIB plugin versions of the tool (<33.2.0, <34.2.0) were
missing the following columns in the data requests table:
* commentsformat
* dpocommentformat
And the upgrade scripts for the merged tool failed in
Moodle 3.3.8+/3.3.0+ failed to add these columns.
So a site which uses the CONTRIB plugin and eventually upgrading to 3.9
will encounter an error during upgrade because of the missing
dpocommentformat column.