Swap if with comparator to get rid of nothing

[zverevgeny]

Currently ssaProgram doesn't support nulls. And so predicate with Nothing can't be pushed down
But in some cases it's possible to get rid of Nothing by rewriting a predicate

example predicate:
(case when household_demographics.hd_vehicle_count > 0
then household_demographics.hd_dep_count/ household_demographics.hd_vehicle_count
else null
end) > 1.2

it can be rewritten to:
if (household_demographics.hd_vehicle_count > 0, household_demographics.hd_dep_count/ household_demographics.hd_vehicle_count > 1.2, false)

[pavelvelikhov]

I don't see how you can rewrite this predicate to get rid of nulls