Add support for passing multiple objects to suspend/resume commands

This change adds support for running `suspend/resume` on multiple
supported resources at the same time. This improves the user
experience by converting

```
flux suspend ks operator && \
flux suspend ks database && \
flux suspend ks app
```

to

```
flux suspend ks operator database app
```

This works for all types of resources (Kustomizations, Sources, etc.)
since it has been implemented at the `suspend.go` and `resume.go`
level.

When the `--wait` flag is passed to the `resume` command, then Flux
will wait for all resources in parallel within a goroutine each.

Each object is only processed once, even if user provided its name
more than once.

If suspension or resuming fails for one object, it is still carried
out for the remaining objects.

As a special case, the old behaviour of `resume` is retained, i.e.
when only one object name is provided, `resume` waits for the object
to become ready even if the `--wait` flag is not provided. In all
other cases the `--wait` flag is always considered.

closes #3746
closes #3793

Co-Authored-By: Max Jonas Werner <mail@makk.es>
Signed-off-by: Rishikesh Nair <alienware505@gmail.com>
Signed-off-by: Max Jonas Werner <mail@makk.es>

cmd/flux/testdata/oci/resume_oci.golden

@@ -1,5 +1,5 @@
 ► resuming source oci thrfg in {{ .ns }} namespace
 ✔ source oci resumed
 ◎ waiting for OCIRepository reconciliation
-✔ OCIRepository reconciliation completed
+✔ OCIRepository thrfg reconciliation completed
 ✔ fetched revision 6.3.5@sha256:6c959c51ccbb952e5fe4737563338a0aaf975675dcf812912cf09e5463181871