PFA patch to fix the issue where while switching the tabs in query tool resets the position of the table viewport to the first row.
RM#2875
Steps:
1) Open query tool
2) Execute:
select * from generate_series(1, 1000) as "column-1";
3) Scroll till the End OR till ~250 row
4) Click on 'Explain' Tab
5) Go back to 'Data output' Tab
Hmm, minor issue; each time I return the to data tab, the data moves up two rows! It's almost like it's calculating the viewport taking into account the row header (e.g. row 250 is visible immediate below the header), but then re-positioning without taking it into account (e.g. row 250 is aligned with the top of the row header, thus making row 252 the first visible one).
