Make logging to stdout work again with implicit `development` env

PR #11060 disabled logging of `rails server` to stdout in non-development environments. It did so by checking whether `-e development` was passed explicitly. However, development environment can also be set using the `RAILS_ENV` or `RACK_ENV` variables or by not specifying an environment at all. In these cases, logging to stdout was suppressed, too. This means that simply running `rails server` would no longer output anything. This PR fixes the problem and adds further tests.