Enhanced hover duplicates function arguments

The enhanced hover handler prints a symbol's parameter list and then also prints the full type of the symbol after the colon. Parameters displayed before the colon are also represented in the function type after the colon.

For example, the hover for the `List` type shows:

```lean
List.{u} (α : Type u) : Type u → Type u
```

This seems to say that `List : Type → Type → Type`.

The notation as shown in the infoview and elsewhere is instead:

```lean
List.{u} (α : Type u) : Type u
```