mgr/telemetry: make sure histograms are formatted in `all` commands

mgr/telemetry: make sure histograms are formatted in `all` commands

I noticed that histograms weren't getting formatted in `preview-all`
and `show-all`. I made a few tweaks so they are properly formatted now.

I verified this fix on:
`ceph telemetry preview`
`ceph telemetry preview-all`
`ceph telemetry show`
`ceph telemetry show-all`

Note that only the `all` commands were affected.

Fixes: https://tracker.ceph.com/issues/58050
Signed-off-by: Laura Flores <lflores@redhat.com>