Support for DoH lookups

[tillson]

One issue I've run into when using zdns is that sometimes, the network firewall intercepts and rewrites DNS lookups (in my case, due to the domain being blocklisted). I don't have the ability to turn this off, so it would be useful if we could circumvent this firewall by leveraging DoH to do mass lookups.

I'd be interested in helping out with the implementation of this but am first wondering whether you all, as the primary maintainers, think that this is in-scope and useful for the zdns project, or if it would be better suited for a different project like zgrab.

Thanks