- Make use of `test.MockVariableValue` to override variables for the
duration of the test.
- Don't needlessly call `onGiteaRun`, its only needed when a HTTP server
needs to be called by the code.
- When `onGiteaRun` is used, make use of the passed parameters, such as
the passed `*testing.T` variable and `*url.URL` (this also avoids
needing to serve the routers in the test code again).
- Use `(*url.URL).JoinPath` to craft new URLs.
- Don't override `setting.AppURL` & `setting.Database.LogSQL` when its
does not affect the test.
- Add empty fixture files for `FederatedUser` & `FederationHost` so they
are truncated and do not persist between tests.
