[Feature Request] Increase amount of error information in output from failed updates and queries

[dandavison]

See #642 (comment)

Note, this update error may contain lots of valuable information beyond just the message appended to "unable to update workflow: ". It may have details, causes, etc. Don't need to solve now (not solved for query either), but we should probably open an issue to provide a better dump of failure upon failure. Same for start update where a validator could provide details. I think for workflow execute we dump the entire close event.