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/navigation/implementations/multiModule/expectClass/common/common.kt

@@ -0,0 +1,12 @@
+package test
+
+open class SimpleParent
+
+expect open class <caret>ExpectedChild : SimpleParent
+
+class ExpectedChildChild : ExpectedChild()
+
+class SimpleChild : SimpleParent()
+
+// REF: [common] (test).ExpectedChildChild
+// REF: [jvm] (test).ExpectedChildChildJvm

idea/testData/navigation/implementations/multiModule/expectClass/jvm/jvm.kt

@@ -0,0 +1,5 @@
+package test
+
+actual open class ExpectedChild : SimpleParent()
+
+class ExpectedChildChildJvm : ExpectedChild()