Adjust code to work with Moodle 3.11

[mattgig]

While the plugin is still working with Moodle 3.11, there is a despreacet call in the module:

get_all_user_name_fields() is deprecated. Please use the \core_user\fields API instead
line 3391 of /lib/deprecatedlib.php: call to debugging()
line 116 of /blocks/lw_courses/renderer.php: call to get_all_user_name_fields()
...

[mattgig]

In Moodle 3.11.3 the plugin seems to procude an invalid course module ID error:

Error
Invalid course module ID
Debug info:
Error code: invalidcoursemodule
Stack trace:
line 236 of /lib/modinfolib.php: moodle_exception thrown
line 1890 of /lib/modinfolib.php: call to course_modinfo->get_cm()
...

I will investigate some further to see whether this is really the case, but don't have the time just now.