Describe the bug

When using .stream() to stream rows as JSON, if an error occurs mid-query, the "exception" appears as a row in the results. This effectively means you need to scan the results for a row containing only "exception". This is costly (not much, but every bit counts) and silly.

If you have a scenario where the query legitimately returns a column named exception, then...well you get the point.

Initially I used StreamReadable.on('error', ...) expecting that listener to be invoked, but it wasn't. On one hand, I guess it makes sense since it wasn't a stream/read related error, but the fact that errors aren't surfaced in a first-class way is a design limitation.

Steps to reproduce

Run a query that will produce an error mid-way through, i.e.

SELECT 
    number, 
    if(number > 420000, throwIf(1, 'BOOM!'), number) AS value
FROM 
    numbers(1000000)

Stream that via ClickHouseClient.query().stream(). You'll see the row with "exception" appears among the results.

Expected behaviour

Errors should be surfaced in a more first-class way. Proposals:

• Ideally each data chunk of results should have an envelope indicating whether an error occurred. That way you would only need to check for an error once per chunk, rather than once per row. Think millions+ of rows, think compression enabled -- it's only a handful of chunks. This would be a difference maker -- and much more elegant.
• Consider having the SDK intercept the error (in a performant way, one way or another) and surface it via the StreamReadable.on('error', ...) listener.
• Dirt simple: instead of "text" you could distinguish it as "error". This would still require checking each row, far from ideal, but a step in the right direction.

Thank you!!