Feature: Allow API to be scope to one or more BU, like users

[jokdbx]

API Keys, as it stands offer access to ALL the data (either ro or rw).

I have a situation where i'd like to provide a API key to a group to be able to use Sal as a source of information (and potentially update machines). However, I want that group to only be able to look at/modify the machines they are responsible for.