[sosreport] allow --profile with -o and -n

Allow the user to fine-tune the set of enabled plugins using the
-o (--only-plugins) and -n (--skip-plugins) options. These add
and remove plugins from the set defined by the active profile(s).

Both options may be specified multiple times, or given lists of
plugins to operate on. E.g.:

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>