Principles: let the caller decide what it needs, but not let the
framework (middleware) guess what it should do.
Then a lot of hacky code can be removed. And some FIXMEs can be fixed.
This PR introduces a new kind of middleware: "PreMiddleware", it will be
executed before all other middlewares on the same routing level, then a
route can declare its options for other middlewares.
By the way, allow the workflow badge to be accessed by Basic or OAuth2
auth.
Fixes: https://github.com/go-gitea/gitea/pull/36830
Fixes: https://github.com/go-gitea/gitea/issues/36859
3f1ef703d5