fix(moderation): notify issuer of moderator rights toggling

Maximilian Fußrequested to merge
m.fuss/web-app:3466-backport-moderator-must-receive-notification-when-toggling-moderation-right-of-a-participant into release/v2.9.x

fix(moderation): notify issuer of moderator rights toggling

Closes #3466 (closed)

(cherry picked from commit a769c841)

Closes #3466 (closed)

Merge request reports