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

idea/testData/quickfix/createFromUsage/createFunction/call/doNotStripPrefix.kt

@@ -0,0 +1,7 @@
+// "Create function 'foo'" "true"
+class Settings
+
+fun isModified(settings: Settings, c: C) = c.<caret>foo(settings)
+
+class C {
+}