Design location/role based AccessChecker

[vivekmittal07]

Design an access control model which can solve requirements for location/role based access control from different partners.

Parent issue - #103

[bashir2]

As mentioned on the parent issue here this is not a Beta launch blocker.

[williamito]

I understand the current plan is to document recommendations for how to implement a role-based AccessChecker; a design doc (or sketch) would still be very useful to act as source material for such documentation.