Juju wait incompatible with juju 3.0

[Bas de Bruijne]

Juju wait has some compatibility issues with juju 3.0:

```
2022-10-20-00:37:24 root DEBUG [localhost]: juju-wait -m foundations-maas:metallb-system -t 14400 --workload --machine-error-timeout 1800 --retry_errors 0 --verbose -x metallb-speaker
2022-10-20-00:37:25 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:37:29 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:37:33 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:37:37 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:37:42 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:37:46 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:37:50 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:37:54 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:37:58 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:38:03 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:38:07 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:38:11 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:38:16 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:38:20 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:38:24 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:38:28 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:38:32 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:38:37 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:38:41 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:38:45 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is allocating since 2022-10-20 00:37:22+00:00
2022-10-20-00:38:50 root DEBUG DEBUG:root:metallb-controller/0 workload status is maintenance since 2022-10-20 00:38:48+00:00
2022-10-20-00:38:50 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is executing since 2022-10-20 00:38:47+00:00
2022-10-20-00:38:54 root DEBUG DEBUG:root:metallb-controller/0 juju agent status is executing since 2022-10-20 00:38:53+00:00
2022-10-20-00:38:58 root DEBUG DEBUG:root:metallb-controller/0 workload status is waiting since 2022-10-20 00:38:58+00:00
2022-10-20-00:39:03 root DEBUG DEBUG:root:metallb-controller/0 workload status is waiting since 2022-10-20 00:38:58+00:00
2022-10-20-00:39:07 root DEBUG DEBUG:root:metallb-controller/0 workload status is waiting since 2022-10-20 00:38:58+00:00
2022-10-20-00:39:11 root DEBUG DEBUG:root:metallb-controller/0 workload status is waiting since 2022-10-20 00:39:08+00:00
2022-10-20-00:39:16 root DEBUG DEBUG:root:metallb-controller/0 workload status is waiting since 2022-10-20 00:39:08+00:00
2022-10-20-00:39:20 root DEBUG DEBUG:root:metallb-controller/0 workload status is waiting since 2022-10-20 00:39:08+00:00
2022-10-20-00:39:24 root DEBUG DEBUG:root:metallb-controller/0 workload status is waiting since 2022-10-20 00:39:08+00:00
2022-10-20-00:39:29 root DEBUG DEBUG:root:metallb-controller/0 workload status is waiting since 2022-10-20 00:39:08+00:00
2022-10-20-00:39:50 root DEBUG INFO:root:All units idle since 2022-10-20 00:39:33.435080Z (metallb-controller/0, metallb-speaker/0, metallb-speaker/1, metallb-speaker/2, metallb-speaker/3, metallb-speaker/4, metallb-speaker/5)
2022-10-20-00:39:50 root DEBUG ERROR:root:ERROR option provided but not defined: --unit
2022-10-20-00:39:50 root DEBUG
2022-10-20-00:39:50 root DEBUG ERROR:root:juju run --format=yaml --unit metallb-speaker/1,metallb-speaker/2,metallb-speaker/3,metallb-speaker/4,metallb-speaker/5 -- is-leader --format=json failed: 2
```

Juju wait shouldn't be electing a leader for metallb-speaker since its wait-excluded, and `juju run` is moved to `juju exec` in juju 3.0.

[Ben Hoyt (benhoyt)]

One thing to note is that Juju 3.0 now has a "juju wait-for" command built in. It can wait for applications, units, and so on, and it takes an optional query expression.