Add operator shelf authorization, apply to relevant viewset, add command line tools for permissions management.

See the testing spec in the bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1074304#c1

r? @robhudson @ngokevin @diox
Do you think that differentiates enough from the object-level permissions implemented here? That was my concern, being clear about the distinction between the two.