mgr/DaemonServer: "osd safe-to-destroy" - more verbose output

mgr/DaemonServer: "osd safe-to-destroy" - more verbose output

For multiple inputs, we want to avoid a situation like:

```
$ ceph osd safe-to-destroy 0 1 2
Error EBUSY: OSD(s) 1,2 have 96 pgs currently mapped to them
$ ceph osd safe-to-destroy 0
Error EBUSY: OSD(s) 0 last reported they still store some PG data, and not all PGs are active+clean; we cannot be sure they aren't still needed.
```

The first command seems to be implying osd.0 is safe-to-destroy whereas it isn't.
This patch instead gives a complete report of each osd if multiple osds are specified.

Signed-off-by: xie xingguo <xie.xingguo@zte.com.cn>