[style-guide] Parameter owner patterns should be consistent with prefix application expressions

Union cases patterns should be consistent with their creation expressions, like this:
```fsharp
let _ = Foo x
let _ = Bar(1, 2)

match s with
| Foo x -> ()
| Bar(1, 2) -> ()
```

Currently Fantomas adds an extra space in the last pattern, which makes it inconsistent. I propose we should fix this.