Allow looking up for first available modem or sim object with the "any" keyword
Or just with "an" or "a"... E.g.:
$ mmcli -m a
--------------------------------
General | dbus path: /org/freedesktop/ModemManager1/Modem/0
| device id: 1a48f1180f1fb0166d91f7b139d027136b59ba63
--------------------------------
Hardware | manufacturer: Sierra Wireless Inc.
| model: Sierra Wireless EM7345 4G LTE
...