Handling updates to different assets

[dbirman]

User story

As a user I might modify the state of a QCMetric in a different asset than the one that I loaded in the portal. Should the portal push that update back to the original asset?

I think we do have to sync at upload time, otherwise if we rely on the indexer to sync assets we run the risk of having someone update two different assets and then we need to do merges (in practice the merge is trivial since everything is timestamped, but form a user's perspective it might not be obvious what happened).

[tbd]