TLSRPT follow-up updates

[Snawoot]

Purpose of proposed changes

• Makes TLSRPT reporting configurable on per-zone basis.
• Send mx_host_pattern attributes along with policy response.

Related #107

Essential steps taken

Moved config property to zone section and updated corresponding references. Also updated structure of ZoneEntry.

Exported MX list from STS policy retaining original * for wildcard names (as the opposite to match list which uses .domain.tld format for wildcards).

CC @wietse-postfix for review.

[Snawoot]

For gmail.com domain I get following response:

user@ws:~/src/postfix-mta-sts-resolver> /usr/sbin/postmap -q gmail.com socketmap:inet:127.0.0.1:8461:myzone
secure match=.gmail-smtp-in.l.google.com:gmail-smtp-in.l.google.com servername=hostname policy_type=sts policy_domain=gmail.com mx_host_pattern=gmail-smtp-in.l.google.com mx_host_pattern=*.gmail-smtp-in.l.google.com

[wietse-postfix]

I have one trivial suggestion, and one that may be harder.

[wietse-postfix]

I found the approve button.

[Snawoot]

@wietse-postfix Thank you for the collaboration!