Translations 2.0

We've migrated our translation scripts in the Home Assisstant Core repository under a single namespace. It can now all be invoked using python3 -m script.translations.

Old commandNew command
script/translations_developpython3 -m script.translations develop
script/translations_uploadpython3 -m script.translations upload
script/translations_downloadpython3 -m script.translations download
script/translations_cleanpython3 -m script.translations clean

This will help us prepare for our Translations 2.0 effort that will clean up translations and make it scale better.