The uninstaller was being built as a side-effect of building `setup.exe`. In
Bug 13852273, that was moved from "somewhere" to part of the windows installer
packaging, which happens after the zip and mar are generated. Since the
installer we ship is actually repackaged from the zip[1], we stopped shipping
translated uninstallers.

This changes things around so that the uninstaller gets translated:
- Explicitly build the uninstaller as part of the L10n repack step.
- Use the same logic to build the installer locally as we do to create the ones
  we ship.

[1] Except on Thunderbird

Differential Revision: https://phabricator.services.mozilla.com/D672

--HG--
extra : rebase_source : 05fe935c1d2a9fbfeef786819bfe5913ed8ef862
extra : source : d6bf22099e2195dcb64c3c3d7700d3edd0850a3a