Navigation: Support "Navigate/Related Symbol" for expects/actuals

#KT-20952 Fixed

idea/testData/navigation/relatedSymbols/multiModule/fromExpectMemberValToActuals/common/common.kt

@@ -0,0 +1,8 @@
+package test
+
+expect class Foo {
+    val <caret>bar: Int
+}
+
+// REF: [jvm] (in test.Foo).bar
+// REF: [js] (in test.Foo).bar

idea/testData/navigation/relatedSymbols/multiModule/fromExpectMemberValToActuals/js/js.kt

@@ -0,0 +1,5 @@
+package test
+
+actual class Foo {
+    actual val bar: Int get() = 1
+}

idea/testData/navigation/relatedSymbols/multiModule/fromExpectMemberValToActuals/jvm/jvm.kt

@@ -0,0 +1,5 @@
+package test
+
+actual class Foo {
+    actual val bar: Int get() = 1
+}