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

idea/testData/refactoring/safeDelete/deleteFunction/kotlinFunction/overrideAndImplement3.kt

@@ -0,0 +1,15 @@
+open class A {
+    open fun foo() {
+
+    }
+}
+
+interface Z {
+    fun <caret>foo()
+}
+
+class B: A(), Z {
+    override fun foo() {
+
+    }
+}