WIP encapsulate marshal error kludgery
Fixes https://github.com/Agoric/agoric-sdk/issues/4310
Please review at this stage, even though it is a WIP Draft. This is because of the need to manage the version skew between the endo repository and agoric-sdk. The API change in this PR is an incompatible break, which needs coordination this PR does not yet provide. But I'd like to postpone thinking about that until we agree on an API that is otherwise good.
I have now enhanced it to be compatible with users of the old interface. The adaptation was ugly, but worth it avoid a more painful upgrade dance. It is now ready for review.
ping
If we try to do this again, we should start a new PR. Closing this one as fatally stale.