[x] most user-facing pallet methods are free to call
[x] only root can register new oracle operators
[x] increased block time to 3 seconds from 2 seconds
Oracle operators were previously free to register by themselves, meaning that anybody could register and would immediately be assigned oracle requests. However, if they don't run the oracle binary, the oracle requests assigned to them will never be answered. Thus, only the root can register operators (so we can initially register trusted operators only).
Registered operators, however, won't automatically get oracle requests assigned; they need to activate their operator first. This means, that only active operators are assigned requests because it is assumed that registered (trusted) operators will run the oracle nodes properly after they activate their node.
Registered operators can deactivate their operator as well, which means that they remove themselves from the active operator set and don't get oracle requests assigned to them. They still remain registered (unless the root deregisters them) and can still reactivate their node and start receiving oracle requests.
Description
Aims to close #91 and close #102
Oracle operators were previously free to register by themselves, meaning that anybody could register and would immediately be assigned oracle requests. However, if they don't run the oracle binary, the oracle requests assigned to them will never be answered. Thus, only the root can register operators (so we can initially register trusted operators only).
Registered operators, however, won't automatically get oracle requests assigned; they need to activate their operator first. This means, that only active operators are assigned requests because it is assumed that registered (trusted) operators will run the oracle nodes properly after they activate their node.
Registered operators can deactivate their operator as well, which means that they remove themselves from the active operator set and don't get oracle requests assigned to them. They still remain registered (unless the root deregisters them) and can still reactivate their node and start receiving oracle requests.