feat: use daemon_name for OpenDKIM sign-verify decision instead of IP

[link2xt]

On FreeBSD 127.0.0.2 is not assigned to any interface by default,
so 127.0.0.2 source address hack cannot be used to make OpenDKIM
verify the signature instead of signing.

This change sets InternalHosts to - so no IP addresses
make OpenDKIM sign the message. Instead of IP address,
OpenDKIM in the outgoing pipeline is explicitly told
to sign messages by setting {daemon_name} macro to ORIGINATING.

This is a replacement for #778

[link2xt]

If this does not fail test_reject_missing_dkim then should be an alternative usable on FreeBSD.

I tested in #783 that the test works.

[link2xt]

This - is used in some OpenDKIM tests:
https://github.com/trusteddomainproject/OpenDKIM/blob/master/opendkim/tests/t-sign-ss-macro.conf#L9

[link2xt]

This is unused because there is no milter.

[link2xt]

This was also unused, it's just a cleanup.

[link2xt]

This is supposed to work: http://www.trusteddomain.org/pipermail/opendmarc-users/2013-June/000153.html

Here is the source code where {daemon_name} macro should be checked against MTA set and set originok to true:
https://github.com/trusteddomainproject/OpenDKIM/blob/5c539587561785a66c1f67f720f2fb741f320785/opendkim/opendkim.c#L11919-L11944

[link2xt]

Seems the problem is that all the OUTGOING stuff works, but final.lua runs even for outgoing messages and this does not work anymore:

relay/cmdeploy/src/cmdeploy/opendkim/final.lua

Lines 1 to 5 in 7191329

	if odkim.internal_ip(ctx) == 1 then
	-- Outgoing message will be signed,
	-- no need to look for signatures.
	return nil
	end

We should not use internal_ip anymore.