fix: raise when an update reader cannot read, and report host status

netOrk reads an empty update list as "no updates" and closes every patch
clock on the host. A refused sudo, a failing pkg, syspatch or freebsd-update,
or a pkg database pkg cannot read used to come back as that empty list. Each
of these now raises. Only pkg's "is not installed" still means no packages.

BsdDriver takes on napalm-device-types' HostStatusMixin. On FreeBSD it
reports a host whose installed kernel differs from the running one as
needing a reboot (device-types 4.1). OpenBSD stays unknown.

Closes #4

napalm_bsd/openbsd.py

@@ -64,10 +64,10 @@ class OpenBSDDriver(BsdDriver):
         updates: list[dict] = [
             {**candidate, "origin": None, "security": None}
             for candidate in parse.pkg_add_candidates(
-                self._out("pkg_add -u -n -v", privileged=True, timeout=300)
+                self._read("pkg_add -u -n -v", privileged=True, timeout=300).stdout
             )
         ]
-        patches = parse.syspatch(self._out("syspatch -c", privileged=True, timeout=120))
+        patches = parse.syspatch(self._read("syspatch -c", privileged=True, timeout=120).stdout)
         if patches:
             installed = parse.syspatch(self._out("syspatch -l", privileged=True))
             summary = (