Misc: Support light-classless classes in inheritors search

In particular, support line markers for expect-classes
and navigation to expect-classes from their base class

 #KT-20329 Fixed

idea/testData/multiModuleLineMarker/hierarchyWithExpectClassPlatformSide/common/common.kt

@@ -0,0 +1,11 @@
+// !CHECK_HIGHLIGHTING
+
+package test
+
+open class <caret>SimpleParent
+
+expect open class ExpectedChild : SimpleParent
+
+class ExpectedChildChild : ExpectedChild()
+
+class SimpleChild : SimpleParent()