KT-38027 Support Code Vision feature in Kotlin

idea/testData/codeInsight/codeVision/ClassInheritors.kt

@@ -0,0 +1,16 @@
+// MODE: inheritors
+
+<# block [ 4 Inheritors] #>
+open class SomeClass {
+    class NestedDerivedClass: SomeClass() {} // <== (1): nested class
+}
+<# block [ 1 Inheritor] #>
+open class DerivedClass : SomeClass {} // <== (2): direct derived one
+class AnotherDerivedClass : SomeClass {} // <== (3): yet another derived one
+class DerivedDerivedClass : DerivedClass { // <== (): indirect inheritor of SomeClass
+    fun main() {
+        val someClassInstance = object : SomeClass() { // <== (4): anonymous derived one
+            val somethingHere = ""
+        }
+    }
+}