fix(apache): default vhost port so vhosts bind an address

[Aman1994]

port is Optional in Eit_types::Web::Apache::Vhost_options, and the profile passed it straight to apache::vhost. When unset, apache::vhost falls back to the resource title for the vhost address, emitting <VirtualHost keyserver_webapp>. Apache cannot resolve that as an address and drops the vhost entirely:

AH00547: Could not resolve host name keyserver_webapp -- ignoring!

Every request then falls through to the default vhost. Hit in prod on dkcphcochlear0{1,2}: the keyserver app vanished and clients got the default docroot's directory index.

Default the port to 443/80 based on ssl, and use it in three places:

• apache::vhost's port, which is the actual fix
• the $listen_ports map, so a portless vhost still opens its firewall port instead of relying on $https/$http happening to cover it
• monitor::domains, which was building https://host: with a trailing colon whenever port was unset

Also add an optional servername passthrough. It defaults to the resource title, which is rarely a resolvable hostname, so a vhost named for the app rather than the site never matches a real Host: header. Leaving it undef keeps the previous behaviour.