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

idea/testData/quickfix/changeSignature/addFunctionParameterLongNameRuntime.kt

@@ -0,0 +1,8 @@
+// "Add parameter to function 'foo'" "true"
+// DISABLE-ERRORS
+
+fun foo(x: Int) {
+    foo(,);
+    foo(1);
+    foo(2, java.util.LinkedHashSet<Int>()<caret>);
+}