In the case of OAuth errors which we get through the message
channel, throwing an exception doesn't help us as the init function
will not be aware about it.
So for now, I've moved the nodejs style error handling in this
particular case.
For now I've mostly tried to follow the same style guide as the flutter
repository, with many options disabled. Eventually, maybe it would make
sense to be far stricter.
In this mode the user doesn't need to do anything but give the
GitJournal app permissions, and then it will go and create the repo, add
the ssh key and everything.
This currently does not work for Gitlab.
This just models the basic API that we need for GitJournal. The API
isn't great and could use improvement.
Also, yes, I know I'm committing the secret key, but I don't see any
other way of managing this. GitHub doesn't allow the implicit oauth flow
or dynamic clients registration or anything. So there isn't really any
other way.
