Optimize "LIMIT" queries for speed / memory with special TopK operator

[alamb]

Is your feature request related to a problem or challenge?

This pattern is common:

SELECT c1, c2
FROM t
ORDER BY c3
LIMIT 10

For example we have queries in IOx like the following (this is the same pattern @NGA-TRAN describes on #7162)

SELECT tag, value1, ...
FROM t
WHERE other_column = 'foo'
ORDER BY time
LIMIT 10

Describe the solution you'd like

If the data IS NOT already sorted, what happens today is a plan like

LIMIT(fetch=10)
  SORT(sort_exprs=[c3] fetch=10)
    SCAN(...)

And the Sort can take partial advantage of the fetch -- and it will be better after @gruuya 's change in #7180

We can probably do better still with a special operator like the following that uses some specialized structure (perhaps some type of heap)

TOPK(fetch=10, sort_exprs=[c3])
    SCAN(...)

Describe alternatives you've considered

If the data is already sorted the right way, DataFusion can just read first N values and stop as described on #7162

Additional context

No response

[alamb]

FWIW I am not sure how much better a special topK operator will be than #7180

[alamb]

I have a PR up with a proposal for a top K implementation if anyone would like to look: #7250