feat(compiler): Make if propagate errors [fixes LNG-202]

[InversionSpaces]

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[linear]

LNG-202 Make `if` propagate errors transparently

Right now if\else work just like try\catch: if error is raised inside if body, it will be captured and else body will be executed.

if 1 == 1:
  Test.test("one")
else:
  Test.test("two")

If Test.test("one") generates error, Test.test("two") is executed