Cleanup translate-server.git

As discussed translate-server.git should removed in future, to have everything in public. The information in translate-server.git will end up in blueprints.

Parent Task: #15085 (closed)

Related issues

Related to #16995 (closed)
Related to #15086 (closed)

Original created by @Hefee on 17063 (Redmine)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information