refactor: change organization of data path to forgejo-contrib #528

Changes Made

The current organization for constructing the data directory for the keys file is Cyborus. This does not reflect the state of the project anymore. The new organization is forgejo-contrib instead. To prevent this becoming a breaking change the keys file will still be read at the old location, as a fallback. The KeyInfo struct will always be saved at the new location, so the user only has to use fj once to perform the migration of the keys file.

It should be noted, that this change only affects users on Windows and macOS. On Linux, only the application part gets used for constructing the project directories, leading to the same path in both versions.

While I was at it, I also replaced the current error reporting there with localized messages.

Code of Conduct

• I agree to act in accordance with the CoC & AI Agreement.
• This contribution was not generated by an LLM, even in part.

As part of the migration the KeyInfo struct now also gets saved as soon as the file has been read from the old location. Failure of that save does not prevent the operation from running, but a warning gets issued to the user.

It may be better for the organization name to be forgejo-cli (or something similar), in case the repo's ownership changes again (i.e. hopefully some day to the forgejo org!)

That would be possible, although to me it changes the logic of the normal path. The old location becomes something normal we just check for, instead of it being something we only use in the case we don't find the file at the expected location. Additionally, it means we always check at the old location first, regardless of whether the file has already been migrated. So I'd prefer to keep the current logic

Rebased onto current main