Outlines the roles used in the ZNS system
Inherited ONLY by
ZNSAccessController
The highest rank, assigns Admins, new roles and Role Admins
The main maintainer role, that gets access to all system functions
This role is here specifically for the ZNSRootRegistrar.sol contract
Executor can be here to future proof, if we need a new role so we don't have to upgrade all contracts
