perf(optimizer): Avoid redundant project for the unnest

[srsuryadev]

Summary:
Avoid unnecessary project for the unnest by pushing the aliasing to the output name of the unnest node.

For the issue: #787

Differential Revision: D91549738

Unit Tests

E2E Tests

buck run axiom/cli:cli

QL> EXPlAIN SELECT a, b FROM unnest(array[1, 2, 3], array[4, 5]) WITH ORDINALITY AS t(a, b, c);
Fragment 0:  numWorkers=1:
-- Unnest[2][dt3.__p6, dt3.__p10] -> a:INTEGER, b:INTEGER
  -- Project[1][expressions: (dt3.__p6:ARRAY<INTEGER>, {1, 2, 3}), (dt3.__p10:ARRAY<INTEGER>, {4, 5})] -> "dt3.__p6":ARRAY<INTEGER>, "dt3.__p10":ARRAY<INTEGER>
    -- Values[0][1 rows in 1 vectors] -> 
       Estimate: 1 rows, 0B peak memory


4.56ms / 4.09ms user / 0ns system (89%)

[meta-codesync]

@srsuryadev has exported this pull request. If you are a Meta employee, you can view the originating Diff in D91549738.