The previous implementation was not stable because `extractDelegateExpression`
has a source depending on extractDelegateExpression, and it led to
inconsistency in lazy and regular mode in the case of labeled expression
```kotlin
val a: String by l@ MyProperty()
```
In lazy mode the source is KtLabeledExpression, but in the regular one
is KtCallExpression
^KT-56551
Dmitrii Gridin
c59ea8bd2a