Use group (minimal GUI) defaults similarly to the user template

Use group (minimal GUI) defaults similarly to the user template

This provides a complete user-group combination for testing of
the template concept before migrating more templates code.

Note that the UI-defaults for group child cnfvars are not the same
as the ones provided in the build_group module which seem to be
too few and the minimal needed for the configuration to be accepted.

When creating an empty GROUP in the UI, these fields are populated:

    1 GROUP,104: "ganz neu"
    2    (1) GROUP_ACCESS_GO_ONLINE_ALLOWED,0: "1"
    3    (1) GROUP_COMMENT,0: ""
    4    (1) GROUP_EMAILFILTER_BAN_FILTERLIST_REF,0: "-1"
    5    (1) GROUP_EMAIL_RELAY_RIGHTS,0: "RELAY_FROM_INTRANET"
    6    (1) GROUP_PROXY_PROFILE_REF,0: "1"

So there is a tad more than just "GROUP_COMMENT" and following the
UI these additional fields should be added and similarly populated.