[2.0] Fixed E_NOTICE being throwing when ->getSingleScalarResult() is called and no result is found. Added coverage for this and also for multiple result (NonUniqueResultException).

Fixing ensure-production-settings task to not throw an exception and instead use the Output object to output an error

Fixing issue with orm:convert-mapping task and dest-path that does not exist yet as well when reverse engineering from-database

[2.0][DDC-493] Added coverage to DDC-493 and optimized DDC-513 unit tests. Previous commit fixed the issue.