bug: correctness issues for CURRENT_ROW for window execution

[comphead]

window execution with current row have correctness issues on multiple tests, which likely caused by the same reason

- window: COUNT with ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW *** FAILED *** (196 milliseconds)
  Results do not match for query:
--
- window: SUM with ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING *** FAILED *** (190 milliseconds)
  Results do not match for query:
- window: SUM with ROWS BETWEEN 2 PRECEDING AND CURRENT ROW *** FAILED *** (190 milliseconds)
  Results do not match for query:

[comphead]

@andygrove I'm planning to work on it this week, please let me know if you need this in 0.13.0

[andygrove]

This doesn't seem urgent for 0.13 IMO.