Give governance the ability to terminate the contract

[Chris-Hibbert]

What is the Problem Being Solved?

Currently a contract can only be terminated by the contract itself (by calling zcf.shutdown() or zcf.shutdownWithFailure(). It would be helpful if governance could shut it down and allow the space to be recovered when no longer useful.

Description of the Design

Zcf has access to the adminNode necessary to call E(adminNode).terminateWithFailure().
The contractGovernor inside a contract has access to ZCF. It could make that accessible to governance, so we could add terminationGovernance to the existing paramGovernance, filterGovernance, and APIGovernance.

This doesn't help #9483 with termination of existing vats, but could be useful in the future.

Security Considerations

We've already addressed the issue of controlling access to these powerful capabilities in the design of overnance, and use of charters.

Scaling Considerations

Will help cleanup in the future.

Test Plan

unit tests should be sufficient.

Upgrade Considerations

Upgraded contracts would have access to this functionality if their governor and charter were also upgraded. Until then, vats have to be terminated with core-evals.