Server/Remote functions

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Is your feature request related to a problem? Please describe the problem.

_No response_

### Describe the solution you'd like

We need Server/Remote functions that resident in web server (backend) and can be called from any blazor mode (ssr/server/webassembly) without any change, hack or wrapper api (by developer!) ?

Sveltekit, Tanstack.Start, Nuxt and others have such features and it will be good to have the same feature in Blazor...

I know someone may said we have "grpc" but this is not pure C# and needs a lot of work and hack in client and server sides...

what we need is pure C# function that called as any normal C# function from anywhere without any extra effort from developer

### Additional context

_No response_