Safe Delete: Move test classes and test data to refactoring directory

idea/testData/refactoring/safeDelete/deleteFunction/kotlinFunction/funExt2.kt

@@ -0,0 +1,11 @@
+package test
+
+import test.foo
+
+class B {
+    val ref = ::foo
+}
+
+fun B.<caret>foo() {
+
+}