mgr/dashboard: Use of crush node class in ECP modal

mgr/dashboard: Use of crush node class in ECP modal

Now the crush node class preselects root, failure domain and device
class in the erasure code profile modal.

Like for crush rule, now also if you try to delete an used ECP you can't
and the info box will show you, what pool is using the profile.

Fixes: https://tracker.ceph.com/issues/44621
Signed-off-by: Stephan Müller <smueller@suse.com>