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

idea/testData/quickfix/createFromUsage/createVariable/parameter/inFunInClass.kt

@@ -0,0 +1,7 @@
+// "Create parameter 'foo'" "true"
+
+class A {
+    fun test(n: Int) {
+        val t: Int = <caret>foo
+    }
+}