Use systemd-resolved to announce hostname via mDNS and LLMNR (#986)

Drop AVAHI and use systemd-resolved to announce hostname via mDNS
and LLMNR. Also continue to offer the _workstation._tcp.local service
since it is used by the CoreDNS mDNS plug-in.

buildroot-external/rootfs-overlay/etc/NetworkManager/system-connections/default

@@ -2,6 +2,8 @@
 id=HassOS default
 uuid=f62bf7c2-e565-49ff-bbfc-a4cf791e6add
 type=802-3-ethernet
+llmnr=2
+mdns=2
 
 [ipv4]
 method=auto

buildroot-external/rootfs-overlay/etc/avahi/avahi-daemon.conf

@@ -1,17 +0,0 @@
-# See avahi-daemon.conf(5) for more information on this configuration
-# file!
-
-[server]
-deny-interfaces=hassio, docker0
-use-ipv4=yes
-use-ipv6=yes
-enable-dbus=yes
-ratelimit-interval-usec=1000000
-ratelimit-burst=1000
-
-[wide-area]
-enable-wide-area=yes
-
-[publish]
-publish-hinfo=no
-publish-workstation=yes

buildroot-external/rootfs-overlay/usr/lib/systemd/dnssd/workstation.dnssd

@@ -0,0 +1,3 @@
+[Service]
+Name=%H [%m]
+Type=_workstation._tcp