introduce variable/occurrences: allow to walk up through anonymous

the current behavior is not transitive as occurrences inside anonymous when selected outside were detected (IDEA-174339)

java/java-tests/testData/refactoring/introduceVariable/AnonymousClass6.java

@@ -0,0 +1,13 @@
+
+class Bug {
+    Bug(String s) {}
+
+    void m(String s) {
+        new Bug(s.substring(1)) {
+            @Override
+            public String toString() {
+                return <selection>s.substring(1)</selection>;
+            }
+        };
+    }
+}