PDI-7243, PDI-11183, PDI-8395  - cummulative fix for JsonOutput step.

Since all this issues is related with Json Output step to avoid conflicts may be better applied in one turn.

PDI-7243 - JSON Output Step throws NullPointerException when previewing no rows
patch applied only for new behavior. Old-compatibility behavior remains same as for old versions.
fix
PDI-11183 - JSONOutput fails when no input rows
fix, junits covers  PDI-7243 and PDI-11183.
PDI-8395 - JSON Output step only outputs last line of transformation if append is not checked
fix + junit tests

Also removed unnecessary dependency for Email steps to reporting package on simple String comparison action.