add missed translations.py file
This was intentionally removed - the previous translation scheme didn't provide all translation strings for algorithms in processing. Instead it only had locally available algorithms - regardless of whether they are actually coming from QGIS or from somewhere else. Eg. this commit contains the ilwis provider and b0dd2af contained local scripts and RAlgorithms (partly even already in french), while algorithms shipped with QGIS (TAUDem, LiDAR; GRASS7 etc.) were missing - probably because required binary were not installed locally.