Added latest version of Japanese language support, thanks to Shiro Tamoto, and fixed some issues in the German and English language files (#22480, #22481, #22483, #22685, #23305)

Fixes: Course Icons are blocked for a regular user (#23308)

Lernmaterial

automatically get a membership

beneath groups and courses

beneath groups and courses

Merge branch 'fix/0022990/5-3/ilobjorgunit-assignuserstoemployeerole-stores-wrong-id' into release_5-3

* fix/0022990/5-3/ilobjorgunit-assignuserstoemployeerole-stores-wrong-id:
  possible fix for mantis bug 0022990

0020393: The chatserver replies to a connect from a client with "invalid namespace"

Pass subdirectory to chatroom server connector to configure the chat server under a path within the url resource

Merge branch 'release_5-3' into 'fix/0022990/5-3/under-circumstances-ilobjorgunit-assignuserstoemployeerole-stores-wrong-id-in-db'

Release 5 3

See merge request ILIAS/Core!82

cannot be changed

.cpp files were allowed already and since .h and .hpp files can have identical contents, it makes little sense to not allow them at all.