Big change in quickfix tests: no stupid test data format with "before" and "after" file prefixes

idea/testData/quickfix/createFromUsage/createFunction/call/thisInClass.kt

@@ -0,0 +1,7 @@
+// "Create function 'foo'" "true"
+
+class A<T>(val n: T) {
+    fun test(): A<Int> {
+        return this.<caret>foo(2, "2")
+    }
+}