Users - Added 'Not in any group' option to the group filter

Exams - Added a possibility to add a supervisor to an exam on all Skhole certified exams

Statistics - Added a possibility for teachers, group leaders and organization managers to subscribe to a monthly statistic report

Whitelabel - Improvements to Subscription service

Lessons - Enabled saving lesson without text format if media is provided

Tasks - Added remind option for tasks

Notifications - Improved "Mark all as read" logic

UI improvements to the learning platform

Fixed titles in the Swedish Skhole

Certificates - Fixed layout of Skhole certificates