Avalon

The last thing I would suggest is doing this as not having a server that is serving data hard wired to your LAN is frankly blasphemy in my book, but any mesh system with additional ports should do what you want, TP Link Deco for example, even some AP's in bridge mode such as the Unifi stuff - i've used NanoStation M5's and bullets like this before, but check it can be set in bridge mode. Again it's a horrific idea for almost all situations and I really wouldn't suggest doing it for a server.