New Server: Generate `net/http`-only code

[jamietanna]

It may be handy for folks to get a purely net/http server implementation, rather than using a router.

This will be made easier by golang/go#60227 but could allow us to boilerplate a lot of the awkwardness that can be had with the standard library when we are doing things like URL path parameters.

(This is a suggestion while I remember, not intent to add it to the codebase unless we get interest!)

Should also include build tags

[jamietanna]

golang/go#61410 is now accepted. We may be able to play around with https://github.com/jba/muxpatterns in the meantime

[jamietanna]

https://eli.thegreenplace.net/2023/better-http-server-routing-in-go-122/

[jxsl13]

thanks for your work. Don't exploit yourself too much and don't overwork yourself.

[jamietanna]

Thanks very much @jxsl13 💜