Minimal Set of Changes to Apply Code Style in release_5-4

Improved lang file entries of cron-jobs for deleting inactive users and users with lo login for a long time - German version

Improved lang file entries of cron-jobs for deleting inactive users and users with no login for a long time

OnScreenChat: Prevented display of message if the username is empty (because of any kind of race condition)

fixed wrong source dbfield for presenting pass finishing date, since the former used is updated during manual scoring and corrections feature

fixed 25736: Schlagwörter bearbeiten » beim Navigieren die Übersicht verloren; additionally show the keywords in overview and fixed tabs and redirects

Certificate: Revise certificate XML template file migration during database update (with massive logging, according to Mantis issue 26222)

Certificate: Revise certificate XML template file migration during database update (with massive logging, according to Mantis issue 26222)

fix for #26175

Test Question Pool: Fixed Mantis issue 26062