Changed group and user ids to 1001 to allow Artemis user to be the own
of /var/lib/artemis-instance and /opt/activemq-artemis. Otherwise the
owner will be root (1000).
This was already done in Dockerfile-centos file.
Fixes the Dockerfiles handling of ANONYMOUS_LOGIN and adds an
EXTRA_ARGS environment variable to allow specifying extra arguments
separate from the username, password and anonymous login options.