Localization Migration

• Add new localization branches to https://gitlab.torproject.org/tpo/translation for:
  • base-browser : all strings we will need for new features in base-browser
  • tor-browser : tor browser specific strings
  • mullvad-browser : mullvad browser specific strings
• Migrate/unify(decide on either dtd, properties or something else) format for required strings out of torbutton and tor-launcher into 'base-browser' branch for :
  • Security Level
  • New Identity
  • Note: ideally this project can be soft-linked into a desktop tor-browser dev environment similar to tor-launcher can be currently; we should do whatever makes the work-flow of adding new strings suck the least and avoid the current hassle we have whenever we want to test torbutton-specific changes
• tor-browser-build project for desktop browser strings which packages desktop strings into a project to be imported into firefox (similar to how tor-launcher + its strings are currently packaged and the tba-translations project)
• update firefox project/build to use new string projects