Forking a repository via the web UI currently requires visiting a
`/repo/fork/{{repoid}}` URL. This makes it cumbersome to create a link
that starts a fork, because the repository ID is only available via the
API. While it *is* possible to create a link, doing so requires extra
steps.
To make it easier to have a "Fork me!"-style links, introduce the
`/{username}/{repo}/fork` route, which will start the forking process
based on the repository in context instead.
The old `/repo/fork/{repoid}` route (with a `GET` request) will remain
there for the sake of backwards compatibility, but will redirect to the
new URL instead. It's `POST` handler is removed.
Tests that used the old route are updated to use the new one, and new
tests are introduced to exercise the redirect.
Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>
f8da672307