tooltip for enums show `[<Struct>] type` instead of `enum`

I noticed minor issue with tooltips, that affects both VS & Rider:

```fsharp
type Foo =
| F = 1
| G = 2
```

Visual Studio (Version 17.10.0 Preview 1.0):

Rider (2024.1 EAP 8):

VS Code+Ionide (v7.18.2):

I believe it should show the same as in Ionide, or at least, not show struct.