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

idea/testData/quickfix/override/overridingWritableAndNotWritableFinalMembers.kt

@@ -0,0 +1,12 @@
+// "class org.jetbrains.kotlin.idea.quickfix.MakeOverriddenMemberOpenFix" "false"
+// ERROR: This type is final, so it cannot be inherited from
+// ERROR: Cannot access '<init>': it is 'private' in 'E'
+// ERROR: 'ordinal' in 'E' is final and cannot be overridden
+enum class E {}
+trait X {
+    final fun ordinal() : Int = 42
+}
+
+class A : E(), X {
+    override<caret> fun ordinal() : Int = 24;
+}