fromWebHandler adapter to use Request -> Response handlers with h3

[nksaraf]

Describe the feature

An adapte analogous to fromNodeMiddleware that adapts a (request: Request) -> Response handler to an h3 event handler

Additional information

• Would you be willing to help implement this feature?

[pi0]

Since h3 1.8 is web native, we have event.request (As normalized Request object) and we can directly return a Reponse from handlers.

Making wrapper would be mainly a shortcut for translating event.request to request but i think it is still something nice for adapter to be supported.

[nksaraf]

Ohh wait i didnt know there was event.request and Response support already.. that makes things incredibly easier

[pi0]

Added in 6305080