Allow syntax to get address of generic function

[S-YOU]

Currently you declare vweb.run<App> and use handle_conn<T>(...) inside the vweb.
That handle_conn function translate to C function like this vweb__handle_conn_main__App
Most of the event loop library use callback to trigger when message arrived, so you need address of that function.

Current syntax does not allow to get generics function like &handle_conn<T> without the call with bracket ().
If you allow the syntax and generate the code same as &vweb__handle_conn_main__App, that would be perfect.

(I got good numbers with pico with vweb, and performance are very close with raw and it is lacking only that functionality. - https://discord.com/channels/592103645835821068/592320321995014154/737145490143051836)