Go to (show) implementations: skip light methods that are generated with DELEGATION or DELEGATION_TO_DEFAULT_IMPLS JvmDeclarationOriginKind

Add some unrelated tests for fake overrides

idea/testData/navigation/implementations/FakeOverride.kt

@@ -0,0 +1,16 @@
+package testing
+
+open class C {
+    open fun <caret>f() {
+
+    }
+}
+
+class A : C()
+
+class B : C() {
+    override fun f() {
+    }
+}
+
+// REF: (in testing.B).f()