Fix formatter for Mongo if called from format
Fix formatter for Mongo if called from format

If formatOne is called from format, the transUnit is already an array that contains the [_id]. 
If formatOne is called from createSingleResponse, it uses toArray which sets the ['id'] field. In this case it  no longer has ["_id'], so it fails. 

This commit fixes this by setting the ['id'] field if the transUnit is not an object and mongo is the storage engine. This way there always is an ['id'] field.
bdebon/LexikTranslationBundle,Rvanlaak/LexikTranslationBundle,rvanlaarhoven/LexikTranslationBundle,BeneyluSchool/LexikTranslationBundle,intexsys/LexikTranslationBundle,ubiedigital/LexikTranslationBundle,Rvanlaak/LexikTranslationBundle,intexsys/LexikTranslationBundle,rvanlaarhoven/LexikTranslationBundle,Atyz/LexikTranslationBundle,lexik/LexikTranslationBundle,Atyz/LexikTranslationBundle,BeneyluSchool/LexikTranslationBundle,Rvanlaak/LexikTranslationBundle,ubiedigital/LexikTranslationBundle,bdebon/LexikTranslationBundle,BeneyluSchool/LexikTranslationBundle,ubiedigital/LexikTranslationBundle,ubiedigital/LexikTranslationBundle,Atyz/LexikTranslationBundle,shakaran/LexikTranslationBundle,shakaran/LexikTranslationBundle,bdebon/LexikTranslationBundle,rvanlaarhoven/LexikTranslationBundle,lexik/LexikTranslationBundle,shakaran/LexikTranslationBundle