Restore snapshot needs to signal when data has been reset

[jandubois]

We need to be able to include the information about the data reset (let's stop calling it factory reset) with the error message, like e.g.

{"error": "restore failed because reasons", "dataReset": true }

That way the UI will now if the data has been reset or not, and can act differently depending on this value.

One thing that isn't clear to me right now: What does the UI do if the JSON stream includes multiple errors? Do we show all, or stop at the first one? Would we need to add dataReset to all of them?

Originally posted by @jandubois in #5844 (comment)