Idea: discover typed api client registrations and provide them as holes in the CEs

it could be interesting to provide typed api registration when typed api clients are provided server side, e.g.

```fsharp

let webAppFactory =
new TestClient()
|> fun x -> x {
API {
// typechecks on return type from api client methods
_.GetName {| Name = "Peter" |}
_.GetAge {| Age = 100 |}
}
}
|> _.GetFactory()

```

or some alternative form