Add an ip listener option to bind a specific local interface

[williamthome]

Description

Add an optional ip listener option that binds a listener to one local interface instead of all interfaces. Unset keeps today's behavior (bind 0.0.0.0 / ::); set it to an address such as {127,0,0,1} to restrict the listener to that interface, so a dev, admin, or metrics endpoint can be reachable only from the local host. The option is honored on every socket the listener opens: plain TCP, TLS, and the HTTP/3 UDP socket, including the ephemeral-port probe, so the pinned port is reserved on the bound address rather than on all interfaces.

roadrunner_listener:start_link(my_listener, #{
    port => 8080,
    ip => {127, 0, 0, 1},
    routes => my_handler
}).

Proof: a loopback-bound listener serves a request over 127.0.0.1 on both TCP and HTTP/3, and a QUIC socket opened with ip => {127,0,0,1} reports that address from sockname/1.

• I have performed a self-review of my changes
• I have read and understood the contributing guidelines