feat: an HA pair's DHCP peers and config sync as facts (4.11.0)

get_dhcp_ha (declared on DhcpServerMixin, optional) is what a DHCP
server's own HA configuration says: on or off, this server's peer name,
each peer's name, role as the server words it, and HA URL.
ConfigSyncMixin.get_config_sync is where a host pushes its configuration
and for which services, by the names get_services reports; sync items
without a service name stay visible under `unmapped`. A driver mixes it
in, no role promises it. Both raise when they could not read.

What the facts mean for a pair -- hot standby, which side to write to --
is the caller's (NetOrk/netork#1125).

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "napalm-device-types"
-version = "4.10.1"
+version = "4.11.0"
 description = "Abstract device-type base classes for NAPALM drivers"
 readme = "README.md"
 requires-python = ">=3.10"