caddy-frontend-N is bad name, it's just frontend-node-N.

This option was useful only during the time, when there were experiments
running on caddy-frontend clusters during switch to HTTP/2.

Currently HTTP/2 is a standard, and there is no reason to disable it globally.

Attention, this change will require manual intervention on the upgraded
cluster with:

sed -i 's/^recipe = caddyprofiledeps/recipe = software/g' .installed*

On each partition.

NAME_BASE is set on top of the file with informative warning, so that
developers are aware of consequences.

instance-slave-caddy-simplified-input-schema.json has been removed, as it is
not useful.

Some profiles were templates and vice versa, which was very
misleading.

The most complex case - no automatic https redirection and usage
of url and https-url is used to check implementation of type:redirect now.

3.7.3 is an "urgent" new release as announced in
https://www.postfix.org/announcements/postfix-3.7.3.html
the old 3.7.2 version seem to have bee removed from mirrors
(see http://postfix.mirrors.ovh.net/postfix-release/official/ for a
mirror with directory index) and was not in shacache.

using link-binary is enough

See merge request !1268

When using pre-commit hook (the one installed by using `npm install`
from the root of the repository), all .json files are checked to be
valid json and formatted according to the ./format-json rules.

These templates were problematic for this script because they are not
really valid json, so name them .json.jinja2 instead of .jinja2.json so
that they are not selected by the pre-commit hook

See merge request nexedi/slapos!1262

See merge request !1267

Move hardcoded values to default values.
Source the whole content of the data-to-vm parameter.

See merge request !1266