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

idea/testData/quickfix/createFromUsage/createFunction/delegateAccessors/var.kt

@@ -0,0 +1,8 @@
+// "Create function 'get', function 'set'" "true"
+class F {
+
+}
+
+class X {
+    var f: Int by F()<caret>
+}