Descendants of ImplicitFunction1 are not accepted where ImplicitFunction1 is expected

```Scala
trait IF1 extends ImplicitFunction1[Int, String]

def if1: IF1 = ???

def foo(f: ImplicitFunction1[Int, String]) = ???

foo(if1)
/*
1 |foo(if1)
  |    ^^^
  |    Found:    IF1
  |    Required: String
*/
```

Seems like unnecessary exception from the LSP.
