Bug 40686: Add a temporary project to fetch Fluent tranlations for base-browser
We are adding a notification to tell users they can change their language. It needs new strings, and I have decided to use Fluent for them, for a series of reasons.
However, it is the first component to use Fluent, and it needs to be translated with Weblate, but we are not moving base-browser to Weblate, yet. So, we are using another branch on translation.git and we need a new project to fetch it, which I am adding with this commit.
Also, I have changed how we manage base-browser translations, and transformed the TT for to a bash for, to keep the Firefox build script shorter, which is helpful for build debugging sessions.
Closes #40686 (closed).
Needs to be merged with tor-browser!443 (merged).