Merge l10n teams bitmask android and desktop

Background: Currently we have 2 projects in transifex, one for android and one for desktop. That means that we have to manage double the amount of teams, have diverging context/translations for the same things.

Plan: Unite them. We will continue to have different resources, but all under 1 project. There are more volunteers active in the android project, so:

• move everything into the Android project: translations, history, teams/people, contexts, resources.
• rename /otf/bitmask then archive it, rename /otf/bitmask-android to otf/bitmask.
• adapt the different references, both in code as for user documentation
• announce.

I've contacted l10nlabs, to help doing this.