Improve error message in pattern matching when we forget to match the payload

[forki]

type Msg = 
| ShowImage of int


let update model (msg:Msg) =
    match msg with
    | ShowImage ->
        model

this is not helpful for newcomers. We should somehow explain that the pattern needs a payload placeholder.

[jwosty]

Giving this a try at #4780

[edgarfgp]

Simplest message IMO should be Expected 1 argument(s) but got 0