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

idea/testData/refactoring/safeDelete/deleteClass/kotlinClass/classInString.kt

@@ -0,0 +1,14 @@
+package test
+
+import test.A
+
+class <caret>A {
+
+}
+
+class B: A {
+
+}
+
+// A
+val a = "A"