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

idea/testData/quickfix/createFromUsage/createFunction/next/createNextFromUsage1.kt.after

@@ -0,0 +1,16 @@
+// "Create function 'next'" "true"
+class FooIterator<T> {
+    fun hasNext(): Boolean { return false }
+
+    fun next(): Int {
+        throw UnsupportedOperationException("not implemented") //To change body of created functions use File | Settings | File Templates.
+    }
+}
+class Foo<T> {
+    fun iterator(): FooIterator<String> {
+        throw Exception("not implemented")
+    }
+}
+fun foo() {
+    for (i: Int in Foo<Int>()) { }
+}