Inlay hints for unmatched patterns on wild cards.

## Is your enhancement request related to a problem? Please describe.

say I have a function

```haskell
data X = A | B | C | D

f :: X -> X -> Bool
f A A = True
f _ _ = False
```

Then sometimes it is not obvious, what kind patterns are subsumed by the wildcards.

## Describe the solution you'd like

What would be really cool would be to have `HLS` show the patterns that haven't been matched as inlay hint on the wildcards.

This would be similar to what the warning shows when just omitting the cases.

## Describe alternatives you've considered

## Additional context