[RFE] support expansion of TLSA settings

[OlafLostViking]

Please... find a better title and edit it! ;-)

I wanted to include a certificate for a XMPP setup. When adding the TLSA records, it gets very... detailed.

...
"tlsa_records": {
    "domain.tld": [
        {
            "host": "@",
            "port": 5222,
            "usage": "dane-ee",
        },
        {
            "host": "@",
            "port": 5269,
            "usage": "dane-ee",
        },
        {
            "host": "xmpp",
            "port": 5222,
            "usage": "dane-ee",
        },
        {
            "host": "xmpp",
            "port": 5269,
            "usage": "dane-ee",
        },
        {
            "host": "rooms",
            "port": 5222,
            "usage": "dane-ee",
        },
        {
            "host": "rooms",
            "port": 5269,
            "usage": "dane-ee",
        },
...

And so on... Common subdomains seem to be "@", "xmpp"/"chat", "rooms"/"conference", "pubsub", "proxy" and "search". If you need the s2s as well as the c2s ports (I'm not yet sure about that...), you'd need ten entries (50 lines with this formatting) in the configuration. Unfortunately, with XMPP you cannot just hint to a "generic service server" like with MX records, but have to use a certificate for the user domain. So the configuration above has to be made for all (virtual) domains.

So it'll be a nice feature if acmebot could expand and combine settings if found in a list like this (just as an example):

...
"tlsa_records": {
    "domain.tld": [
        {
            "hosts": [ "@", "xmpp", "rooms", "pubsub", "proxy", "search" ],
            "ports": [ 5222, 5269 ],
            "usages": [ "dane-ee" ],
        }
    ]
}
...