contractGovernor holds contract's paramManager; on upgrade, reference is broken

[Chris-Hibbert]

Describe the bug

The otherwise reachably durable contract governor holds onto the governed contract's ephemeral paramManager. If the governed contract upgrades, the ephemeral object turns into a pumpkin.

To Reproduce

This bit the auctions and vaults coreEval in RC2, necessitating RC3.

Expected behavior

Upgrading the contract shouldn't break its governor.

Additional context

In contractGovernorKit.js, we check to see if we have a saved version of the paramManager, and use it if we do. If the contract has been upgraded, sending a message to this object will fail. We can catch that error, and call provideParamGovernance() again when that happens.

        provideParamGovernance() {
          if (!paramGovernance) {
            const { timer } = powers;
            const { creatorFacet, instance } = this.state;
            paramGovernance = setupParamGovernance(
              E(creatorFacet).getParamMgrRetriever(),
              instance,
              timer,
              () => this.facets.helper.getUpdatedPoserFacet(),
            );
          }
          return paramGovernance;
        },