feat: FreeBSD and OpenBSD drivers, read side

FreeBSDDriver (`freebsd`) and OpenBSDDriver (`openbsd`) on a shared
BsdDriver, for the BSD VMs netOrk provisions and BSD hosts added by hand
(NetOrk/netork#798).

- SSH over exec channels (napalm-device-types' run_on_transport): no PTY,
  stdout and stderr apart, real exit codes; run_command()/open_stream()
  are public. Root through `sudo -S` with the password on stdin, or
  `sudo -n` without one.
- Facts: hostname, release and running kernel (freebsd-version / uname),
  hardware from SMBIOS (kenv) or hw.* sysctls, uptime from kern.boottime.
- Interfaces and addresses (ifconfig -a: ether/lladdr, hex netmasks,
  scoped IPv6), routes (netstat -rn, OpenBSD's abbreviated networks
  written out, host/broadcast/loopback entries left out), ARP (FreeBSD's
  sentences, OpenBSD's table), users and groups, processes (lstart read as
  one five-word field), cron jobs (system crontab and the login user's).
- Parsers are pure functions, tested on output recorded from FreeBSD 15.1
  (hand-installed and cloud image) and OpenBSD 7.9 (NetOrk/netork#793),
  with internal addresses replaced by documentation ranges.

tests/fixtures/openbsd-vm/cat_etc_passwd.txt

@@ -0,0 +1,70 @@
+root:*:0:0:Charlie &:/root:/bin/ksh
+daemon:*:1:1:The devil himself:/root:/sbin/nologin
+operator:*:2:5:System &:/operator:/sbin/nologin
+bin:*:3:7:Binaries Commands and Source:/:/sbin/nologin
+build:*:21:21:base and xenocara build:/var/empty:/bin/ksh
+sshd:*:27:27:sshd privsep:/var/empty:/sbin/nologin
+_portmap:*:28:28:portmap:/var/empty:/sbin/nologin
+_identd:*:29:29:identd:/var/empty:/sbin/nologin
+_rstatd:*:30:30:rpc.rstatd:/var/empty:/sbin/nologin
+_rusersd:*:32:32:rpc.rusersd:/var/empty:/sbin/nologin
+_fingerd:*:33:33:fingerd:/var/empty:/sbin/nologin
+_x11:*:35:35:X Server:/var/empty:/sbin/nologin
+_fc-cache:*:36:36:Font configuration cache:/var/empty:/sbin/nologin
+_unwind:*:48:48:Unwind Daemon:/var/empty:/sbin/nologin
+_traceroute:*:50:50:traceroute privdrop user:/var/empty:/sbin/nologin
+_ping:*:51:51:ping privdrop user:/var/empty:/sbin/nologin
+_unbound:*:53:53:Unbound Daemon:/var/unbound:/sbin/nologin
+_dpb:*:54:54:dpb privsep:/var/empty:/sbin/nologin
+_pbuild:*:55:55:dpb build user:/nonexistent:/sbin/nologin
+_pfetch:*:56:56:dpb fetch user:/nonexistent:/sbin/nologin
+_pkgfetch:*:57:57:pkg fetch user:/nonexistent:/sbin/nologin
+_pkguntar:*:58:58:pkg untar user:/nonexistent:/sbin/nologin
+_spamd:*:62:62:Spam Daemon:/var/empty:/sbin/nologin
+www:*:67:67:HTTP Server:/var/www:/sbin/nologin
+_isakmpd:*:68:68:isakmpd privsep:/var/empty:/sbin/nologin
+_rpki-client:*:70:70:rpki-client user:/nonexistent:/sbin/nologin
+_bgplgd:*:71:71:bgplgd Daemon:/nonexistent:/sbin/nologin
+_syslogd:*:73:73:Syslog Daemon:/var/empty:/sbin/nologin
+_pflogd:*:74:74:pflogd privsep:/var/empty:/sbin/nologin
+_bgpd:*:75:75:BGP Daemon:/var/empty:/sbin/nologin
+_tcpdump:*:76:76:tcpdump privsep:/var/empty:/sbin/nologin
+_dhcp:*:77:77:DHCP programs:/var/empty:/sbin/nologin
+_mopd:*:78:78:MOP Daemon:/var/empty:/sbin/nologin
+_tftpd:*:79:79:TFTP Daemon:/var/empty:/sbin/nologin
+_rbootd:*:80:80:rbootd Daemon:/var/empty:/sbin/nologin
+_ppp:*:82:82:PPP utilities:/var/empty:/sbin/nologin
+_ntp:*:83:83:NTP Daemon:/var/empty:/sbin/nologin
+_ftp:*:84:84:FTP Daemon:/var/empty:/sbin/nologin
+_ospfd:*:85:85:OSPF Daemon:/var/empty:/sbin/nologin
+_hostapd:*:86:86:HostAP Daemon:/var/empty:/sbin/nologin
+_dvmrpd:*:87:87:DVMRP Daemon:/var/empty:/sbin/nologin
+_ripd:*:88:88:RIP Daemon:/var/empty:/sbin/nologin
+_relayd:*:89:89:Relay Daemon:/var/empty:/sbin/nologin
+_ospf6d:*:90:90:OSPF6 Daemon:/var/empty:/sbin/nologin
+_snmpd:*:91:91:SNMP Daemon:/var/empty:/sbin/nologin
+_ypldap:*:93:93:YP to LDAP Daemon:/var/empty:/sbin/nologin
+_rad:*:94:94:IPv6 Router Advertisement Daemon:/var/empty:/sbin/nologin
+_smtpd:*:95:95:SMTP Daemon:/var/empty:/sbin/nologin
+_rwalld:*:96:96:rpc.rwalld:/var/empty:/sbin/nologin
+_nsd:*:97:97:NSD Daemon:/var/empty:/sbin/nologin
+_ldpd:*:98:98:LDP Daemon:/var/empty:/sbin/nologin
+_sndio:*:99:99:sndio privsep:/var/empty:/sbin/nologin
+_ldapd:*:100:100:LDAP Daemon:/var/empty:/sbin/nologin
+_iked:*:101:101:IKEv2 Daemon:/var/empty:/sbin/nologin
+_iscsid:*:102:102:iSCSI Daemon:/var/empty:/sbin/nologin
+_smtpq:*:103:103:SMTP Daemon:/var/empty:/sbin/nologin
+_file:*:104:104:file privsep:/var/empty:/sbin/nologin
+_radiusd:*:105:105:RADIUS Daemon:/var/empty:/sbin/nologin
+_eigrpd:*:106:106:EIGRP Daemon:/var/empty:/sbin/nologin
+_vmd:*:107:107:VM Daemon:/var/empty:/sbin/nologin
+_tftp_proxy:*:108:108:tftp proxy daemon:/nonexistent:/sbin/nologin
+_ftp_proxy:*:109:109:ftp proxy daemon:/nonexistent:/sbin/nologin
+_sndiop:*:110:110:sndio privileged user:/var/empty:/sbin/nologin
+_syspatch:*:112:112:syspatch unprivileged user:/var/empty:/sbin/nologin
+_slaacd:*:115:115:SLAAC Daemon:/var/empty:/sbin/nologin
+_dhcp6leased:*:116:116:DHCP6Lease Daemon:/var/empty:/sbin/nologin
+_lldpd:*:119:119:LLDP Daemon:/var/empty:/sbin/nologin
+nobody:*:32767:32767:Unprivileged user:/nonexistent:/sbin/nologin
+netork-user:*:1000:1000::/home/netork-user:/bin/ksh
+hashtest:*:1001:1001::/home/hashtest:/bin/ksh