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

idea/testData/quickfix/createFromUsage/createFunction/set/createSetFromUsage1.kt.after

@@ -0,0 +1,10 @@
+// "Create function 'set'" "true"
+class Foo<T> {
+    fun <T> x (y: Foo<List<T>>, w: java.util.ArrayList<T>) {
+        y["", w] = w
+    }
+
+    private fun set(s: String, w: T, value: T) {
+        throw UnsupportedOperationException("not implemented") //To change body of created functions use File | Settings | File Templates.
+    }
+}