Support for Redis with ACL

I would like to ask whether someone has any experience and/or was able to setup redis 6.0+ with ACL enabled with Chirpstack. As I could see the config files, Chirpstack seems to accept only a password, not a username, while with redis 6.0+ using ACL (I believe the current stable is 7.x) one needs to add both, username and password. For security purposes it is better to disable the default user which is by default enabled. Username thought does not seem to be available for setup looking at the Network and Application Server config files.

I would welcome pull-requests for this, but I would prefer to implement this in the v4 repository: