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

idea/testData/quickfix/createFromUsage/createVariable/localVariable/inWhen.kt

@@ -0,0 +1,12 @@
+// "Create local variable 'foo'" "true"
+
+fun test(n: Int): Int {
+    return when (n) {
+        1 -> {
+            <caret>foo
+        }
+        else -> {
+            n + 1
+        }
+    }
+}