[Feature request] add new type always_null to local-zone similar to always_nxdomain

[TheteSigma]

DNS blacklists currently like to use nxdomain or a network null (0.0.0.0 and ::).
Unbound currently already supports a shortcut for nxdomain like:
local-zone: "example.com" always-nxdomain

Would like to have a similar shortcut for null network like:
local-zone: "example.com" always-null

which would replace the working form:
local-zone: "examplel.com" redirect
local-data: "example.com A 0.0.0.0"
local-data: "example.com AAAA ::"

dnsmasq 2.80 added a similar ability:
address=/example.com/#

Unbound is able to better handle large DNS block lists then dnsmasq.
250k domains to block has almost no impact on Unbound, while it adds 30ms to the query time for dnsmasq.

This feature would make it easier to create large blocklists with the a third the number of configuration lines.

[wcawijngaards]

Okay implemented, the syntax is local-zone: "example.com" always_null

[TheteSigma]

Thank you for implementing and the quick turn around.