All the setup/teardown/pre/post/conditions template methods
now are required to return void. This was warned with phpunit 7
and now is enforced.
At the same time, fix a few wrong function names,
provider data and param types, return statements...
Two modes of visibility checking are supported, depending on the value
of the 'messagingallusers' site setting (site-wide messaging):
- If site-wide messaging is enabled, a user may only be returned in
search results if the searching user can view their profile somewhere
(either the site profile or any course profile).
- If site-wide messaging is disabled, a user may only be returned in
search results if the searching user shares a course with them and can
view their course profile in the shared course.
cescobedo